According to some reports, users are seeing scrollable vertical videos within the app as part of a new user interface for the app that includes a Discover button at the bottom alongside your library, search and home buttons.
This test was spotted by product designer Chris Messina, who saw the extra button when using the beta version of the Spotify app:
Not only that, @Spotify Discover is basically a pared down version of a TikTok-style feed of vertical music videos (likely using their canvas format) that you can like or skip.#NewSpotify pic.twitter.com/hpOEZ8v9bl— Messina.eth (@chrismessina) November 24, 2021
When clicked that button launches a full-screen short-form music video which appears to be snippets of official music videos from various artists. The system will be fairly familiar to anyone who has used TikTok and other similar style video systems already as a flick up and down will change between the videos on offer and users find more content to watch.
As we already know, Discover is Spotify's system for helping users to find new music similar to their current taste, so this new video mode is simply an expansion of that. It is, however, just a test currently and there's no word on whether it will become official.