Spotify has introduced videos previously, but its not a major part of its app yet. And music videos are hard to spot or aren't even available for many songs and albums on the app. However, it appears that this might be about to change since the app has been spotted testing a new tab.
Jane Wong, a reverse engineering expert who has discovered many upcoming features of various social media apps has found out that Spotify engineers are testing a new video tab on the now playing UI, to add it right beside the Album Art and Canvas tabs.
If you aren't aware of what Canvas is, it is a feature on Spotify that displays a video clip instead of album art. It does not show full videos but little animations.
You can't find anything on the tab though, the app only displays a text that reads: "Thanks for your interest in video. We're still exploring what could happen here." By this, we get the idea that it is most likely to be a separate full music video tab to make an introduction.
There's no official news on this from the company yet so there is a chance that this feature might not even see the light of the day. So even if this is a test, it goes to show that Spotify is making the effort to keep users engaged on the app.