The Twitter Inc. logo (Andrew Harrer/Bloomberg)

Many Twitter users have started to notice something different on their Twitter timeline: Tweets from people they don’t follow.

Here is an example of what you might have seen:

It could just be another experiment among the many Twitter has been rolling out to users. But the company recently added a supporting paragraph on its help center explaining: What’s a Twitter Timeline? Your home timeline displays tweets from accounts you have chosen to follow, and promoted tweets or retweets.

“Additionally,” the company says, “When we identify a Tweet, an account to follow, or other content that’s popular or relevant, we may add it to your timeline. This means you will sometimes see Tweets from accounts you don’t follow. We select each Tweet using a variety of signals, including how popular it is and how people in your network are interacting with it. Our goal is to make your home timeline even more relevant and interesting.”

It was a tricky experiment that not everybody liked. But it seems to be official now since Twitter has added the above paragraph. This “favorites-turn-into-retweets” feature has irritated some users who thought it compromised their effort in customizing the twitter feed, and that Twitter is looking more like Facebook.

Favorite, the small star icon showing next to a tweet, is generally used when you want to save that tweet for later, show a soft acknowledgement or simply let that user know you liked or saw the tweet.

With this new feature, some people may think twice before they think they can quietly “favorite” anything.