The thing about the white-ground, or where I may be able to help Flickr ...
... oddly galleries generally have white walls for a reason, well a few reasons. Firstly, it reflects light around the space to give even illumination, and the white surround to artworks ensures the viewers eyes are stopped-down which not only improves resolution but also helps with our colour perception ... the colour receptors in the human eye become less efficient as the light-value reduces.
Secondly, Completion, much of a photo's composition is often a result of the Gestalt completion effect, and if there isn't enough ground between images that effect is lost.
Lastly, Ground-Figure organisation is a necessity for recognising objects through vision, in effect without isolating something from it's surroundings it is very difficult to see it, which is why I use the bloody thing in the first place.
... there, is that constructive enough?