Twitter announced Monday that media extras such as photos, GIFs, and videos along with quoted tweets and user polls will no longer "use up" the 140-character limit per tweet.

Excluded from Monday's update was the removal of counting usernames in a reply or mention toward the 140-character limit, which was announced in a blog entry on the relaxation of character limits this May. A Twitter spokeswoman, who spoke on the condition of anonymity because Twitter is still testing this feature, said that the company will introduce it to a small group of users in the coming weeks before rolling it out to everyone. She did not confirm a specific date for the update.

In its May blog entry, Twitter said that the new features would help users "do even more" with their tweets. "We’re exploring ways to make existing uses easier and enable new ones, all without compromising the unique brevity and speed that make Twitter the best place for live commentary, connections, and conversations," the blog post states.

One update outlined is removing space-taking usernames in replies and mentions. In a demonstration video for how the replies function will soon look, “@username” is no longer included, relying on the thread line visual to show different tweets in a conversation. The names of users involved in the conversation are displayed above the tweet after the text "replying to."

Another feature in the May blog post missing from Monday's rollout was the update that would make all replies appear on a user's feed, making it unnecessary to use ".@" when trying to display replies to a user's audience. Twitter did not confirm if this feature is being tested or when users can expect it in the future.

This product change comes during a rocky period for a company that has seen declining revenue growth and stock value in recent years. Twitter reported that this last quarter saw the slowest revenue growth for the company since it went public in 2013. The platform has struggled to expand its user base and drive up engagement beyond its core group of devoted users, which in turn affects advertising interest. Twitter and co-founder Jack Dorsey has cited streamlining the site's user experience, including excluding mentions and links in a tweet's character limit, as one part in the effort to attract new users.

Rita McGrath, a professor at Columbia Business School that focuses on business strategy, says that the relaxation of character limits could be a way to encourage users to post more images and videos, which some research has shown captures more users for longer. "They want their content to be more engaging," she said. "If you can't keep people on the site and sharing to the site, where are advertiser's dollars going?"

In New York Stock Exchange composite trading, Twitter fell 3.9 percent, to $18.36 a share.