Comment 3 for bug 170533

I the main issue I've run into on initial testing of the patch is some layers not showing previews (I guess the "hidden" you mentioned?) even though the content should be pretty visible in a preview.

As for best size for thumbnails, great Q... it appears that GIMP has a fixed width, but varies the height. It appears your approach is the similar (it looks like theirs can actually modify the height of the layer in the dialog, which seems weird), however it looks like yours implementation currently has the previews top-aligned, is this a mis-perception on my part?

I will go ahead and upload an example file where I'm seeing things with non-visible previews and shoot the link to you and su-v privately (a file I don't feel like sharing with the world).

Looking good so far imho!