I used to have icons for my packages, but since version 12.1 those are not working anymore.
It used to be a 50x50 pixel gif and they worked fine but no longer.
The thumbnail and icon plot themes is Mathematica generate 36x36 pixel and 100x100 images, respectively. However i tried various image dimensions and formats bot none seem to work in the paclets.
This used to be the syntax to make it work.
