User blog comment:Dopp/Technical Update: January 10, 2012/@comment-3235402-20120114174609/@comment-1025281-20120115103019

By "skin option", do you mean in Wikia's rearranged Special:Preferences? The skin option is under the "My Info" tab under a section labelled "Appearance"... are you seeing this? The reason given for this rearrangement (from above): "We're updating your User Preferences page so that items are grouped and listed in a way that's clearer and more useful (for example: all email notification settings will now be in the same section)."

JPG and JPEG are different extensions for the same image format. In theory, there should be no difference between using either of them.