Thank you Nalates for your detailed reply. I appreciate your response.
My point for this particular feature, is that outfit gallery images should not be put in a cache at all. They should be stored in full resolution for the client to be able to call up rapidly whenever needed. If the cache is the only mechanism available for outfit gallery image storage, then these images should not be flushed from the cache based on usage. Having an outfit gallery feature displaying blurry photos is less than useful. It is an implementation fail.
Reading your helpful technical descriptions I now suspect that nothing special was done when implementing images for the outfit gallery. And blurry outfit gallery images suffer from the same issue that plagues profile photos and other GUI elements of the client. In my opinion, we'd be better served having profiles and outfit galleries as separate windows from the client, implemented in a web browser. At least we would be able to see them reliably all the time.