"Photo bombing" refers to the act of unexpectedly appearing or doing something funny in someone else's photo, often causing surprise or laughter. Full definition
Okay, it is not my puppy This cute dog was just simply the most perfect photo bomb ever! (thefashionrose.com)
However, bad photos — and even photo bombs — are still typical of the majority of men's profiles (girls are typically better at that). (blogs.elenasmodels.com)
Getting photo bombed by climate activists during an appearance before the Vancouver Board of Trade in January is unlikely to change Stephen Harper's commitment to diversifying Canada's energy markets. (canadianbusiness.com)