In general, to "skin" something means to wrap a design around it, for example: "We finished coding the widget, now we just need to skin it and get it in syndication."

A "skin" can also refer to a type of video ad that does not interfere with the video, as a pre-roll does, because it is displayed on the video player instead of within the actual video.

See also : browser skins  
NetLingo Classification: Online Jargon