If you mean thumbnails in terms of showing the videos thumbnail in the RPC - no. It sadly isn't possible to do this anymore. I've tried out many different ways and read through many documentations but couldn't find a way to make it work.

On the other hand I wanted to implement a list of different pictures you can choose instead of the current one. I took a short break due to personal reasons, but I’m working on it again now!

P.S. If you (or anyone else reading this) knows of a way to implement thumbnails feel free to text me on Discord (Aqusorias) or make a pull request on GitHub!