themes page has broken thumbnail images

[WoofGrrrr]

Describe the problem and steps to reproduce it:

Steps to reproduce:

https://addons.thunderbird.net/en-US/thunderbird/ (both Thunderbird & FF) Click Themes Click Abstract

What happened?

Actual results:

Thumbnail images show "puzzle" icon

What did you expect to happen?

Expected results:

show thumbnails for themes

Anything else we should know?

(Please include a link to the page, screenshots and any relevant files.)