Based on the search results, it seems that "what the dog doin" is a popular phrase used in memes and GIFs featuring dogs. There are several GIFs available online that use this phrase, including a smiling dog GIF, a handstand dog GIF, and a GIF with a dog looking around. It is unclear what the original source of this phrase is or what it means exactly, but it appears to be a humorous way of commenting on a dogs behavior or expression.