The phrase what the dog doing became a widely shared internet joke used whenever a dog appears in an unexpected place or acts strangely. Short clips using the line spread through meme edits, reaction videos and pet compilations, where the sound is added after recording rather than taken from the original footage. Its popularity comes from its versatility, fitting everything from a dog sitting in a fridge to one simply looking guilty. Creators still reuse it because audiences recognise the setup immediately without needing any context.