If you're familiar with the YouTube homepage (where it displays videos in rows by topic) you can usually scroll down and find one of the cards a sort of colorful "Show me something different" card instead of a regular video card.

I putzed around with YouTube for a bit and was unable to get it to come up but it's a pretty rare thing to see - it's possible it was a limited time feature trial but it also just might require a lot of weird actions to summon. I swear I have seen it before and it wasn't just a fever dream though!