This is a request to make the site's icons have transparent backgrounds. They are already PNGs, so they support that. This would make applications such as Droidstack look much better.
Although stackapps is the only one that has a non-white background, all the others have solid white backgrounds. Although this is not immediately annoying, it suddenly becomes so when putting a different background on an icon (for example when clicking on an item in Droidstack, the background turns orange but there's a nasty white square around the icon.. I'll try to upload a new video of it soon).
icon_url
images as returned by some API calls.