Newly-drawn 3D thumbnails look glossy

It seems newly-drawn 3D thumbnails have a more glossy look than they should. Just enable 3D thumbnails on any items created recently and you’ll see that they look more glossy than their 2D thumbnails.

The same applies to characters too. The shine on a friend’s 3D avatar thumbnail looked fine, but after asking him to re-draw it it looked more glossy.