The day after Thanksgiving, nearly one month after Elon Musk became the owner of Twitter, he returned to one of his hobby horses. “I’m just fighting for free speech in America,” he wrote in a tweet.

One of 28 that he posted that day — beginning just after midnight, following messages about how tasty his holiday meal was — the free speech tweet was in response to two followers who were aggrieved about how Mr. Musk was being treated since acquiring the social network in late October. The post was liked more than 46,000 times.

Mr. Musk has often said that Twitter needs to be more open and filled with a greater diversity of voices and points of view. But Mr. Musk’s Twitter feed is often an echo chamber. He regularly sees, likes and replies to messages that are about him or are posted from accounts that often act as his cheerleaders, according to a New York Times review of his activity on the platform.

In order to assess how the social network may evolve under Mr. Musk’s watch, The Times reviewed nearly 20,000 of his tweets, analyzing posts from recent years and images he published over the past decade, as well as the relatively small number of users that he follows.

What Mr. Musk says on Twitter has a huge reach, now more than ever: His audience is one of the largest, with nearly 128 million accounts following him. It is where he solicits advice, conducts polls, condemns censorship and announces sweeping policy changes on the platform. As a power user who now controls the company — he recently called himself the “chief twit” — Mr. Musk has vowed to remake the social network in his vision.

Of the 178 accounts that Mr. Musk followed as of Tuesday, most were related to his businesses, or have expressed admiration of his business style, the Times review found. The list is heavily male: Only two dozen that are not institutional or organizational accounts belong to women. He is related to two of them — his mother, Maye, and sister, Tosca — and was married to a third.

Amid discussions of Twitter policies, internet satellites from SpaceX and Tesla software updates, his posts have a freewheeling quality to them. He traffics in juvenile humor and vulgar jokes (pictures of tape dispensers laid in sexual positions), scientific marvels (the Large Hadron Collider), popular subjects on far-right sites (Pepe the Frog) and critiques of divisive cultural issues (“I’m not brainwashed!!”).

Mr. Musk’s posting style is conversational, and regularly satirical. He messages with former Democratic cabinet officials, criticizes news organizations and trades barbs with venture capitalists.

“The purchasing of Twitter was a power move, politically,” said Joan Donovan, the research director of the Shorenstein Center on Media, Politics and Public Policy at Harvard. “He is one of the richest man in the world buying a social media company in a move that is expressly about politics and influence on culture and on media.”

Often, his updates are limited to just memes — joking images or videos that are copied and widely shared. Many have origins on fringe sites or cryptocurrency message boards that are popular with his followers. Some are about him. Some appear to be original.

Mr. Musk did not respond to a request for comment about his activity. At Twitter, as with many of his other companies, Mr. Musk has no traditional press team. Instead, he tweets.

Since he created his account in June 2009, Mr. Musk has posted more than 21,000 times. In recent years, that has meant posting all hours of the day, most days of the week.

Mr. Musk has “made himself unignorable by becoming king of Twitter,” Ms. Donovan added.

Over a 48-hour period in November, a moment when he touted record activity on the social network under his leadership, Mr. Musk posted 60 times. His posts included commentary on the collapse of a cryptocurrency and combative responses to critiques about his workplace policies. In one instance, he issued a decree about parody accounts after users changed their profile names to imitate him.

Many of his missives quickly became popular among his followers.

It is unclear exactly what Mr. Musk sees in his feed. The exact sequence depends on whether he has chosen to receive algorithmic recommendations or just tweets from accounts he follows. (He has previously tweeted that people are being “manipulated by the algorithm.”)

His activity increasingly consists of replying to users who have mentioned him. When he responds to accounts that he does not follow, he frequently chooses those that have complimented or praised him: In dozens of instances over the past six months, according to the Times analysis, he has replied to tweets from users whose account descriptions mention that they support or invest in companies owned by Mr. Musk, or that they are fans of his leadership.

There are times when he second guesses what he broadcasts.

Over the past two years, he has deleted hundreds of tweets within hours of posting them. According to the PolitiTweet website, which archives all of Mr. Musk’s tweets, he has also deleted dozens of tweets in the months since he acquired Twitter.

On Nov. 14, for example, Mr. Musk tweeted that he would be “working and sleeping” at Twitter’s headquarters in San Francisco until the site was fixed.

A website tracking Mr. Musk’s private jet movement suggested that he traveled away from San Francisco around that time. He deleted the tweet 18 hours after first posting it.

But for a person with as large a follower base as Mr. Musk has, deleting tweets may do little to change how widely seen or influential those posts become when they are first published.

“Millions of people see his tweets, not many will notice when they are deleted,” Ms. Donovan said.

Many tweets that have landed Mr. Musk in hot water remain online.

In 2018, a few weeks after Mr. Musk had smoked marijuana during an on-camera interview for Joe Rogan’s podcast, Mr. Musk tweeted that he had the funding to take Tesla private at $420 a share.

Experts began to question whether his entire feed was being produced in jest, and pointed out the repeated marijuana references in his tweets (including his proposed funding price).

That incident led to charges from the Securities and Exchange Commission, and later a settlement that included monitoring of what Mr. Musk could post about Tesla on Twitter. Shareholders are now also seeking billions of dollars in damages in a lawsuit after Mr. Musk’s takeover proposal never materialized.

Last week, Mr. Musk joined an investor call as Tesla reported its recent quarterly earnings, which showed a respectable jump in profits despite a growing list of problems plaguing the company. The automaker’s mixed performance last year had led many to question whether Mr. Musk’s focus and attention on Twitter had meant that he was neglecting his duties at Tesla.

Mr. Musk deflected that criticism on the earnings call, suggesting that his millions of Twitter followers were a sign of his popularity.

“I might not be popular with some people,” he said, “but for the vast majority of people, my follower count speaks for itself.”