Instgaram is testing a video progress bar for videos on feed, letting you skip forward or rewind back to a point you want to watch.
Previously, users had no control over the video's progress, if you wanted to skip to a part of the video, you wouldn't be able to do that, you'd have to wait for the whole video to get over. Although, the feature was available for videos on IGTV.
Additionally, Instagram is also testing a few more features, like "Add Lyrics" for Music Stories. Instgram Music, that has recently been available in India, will probably soon let you add lyrics to the songs.
Also Read: Instagram’s tests and updates: Categories on Explore, pop-up for offensive comments, and more
IGTV is testing confirmation screen after tapping "See Fewer Posts Like This". The feature is kind of similar to the "Sensitive Content" warning shown on videos that might not be suitable for the whole audience, giving the user control over what he sees on the platform.
Similarly, the feature would prompt, that you'll see fewer videos like this from now on, if you choose to tap on "See fewer posts like this".