To photobomb / to bomb a photo (verb): spoil a photograph by unexpectedly appearing in the camera’s view as the picture is taken.
Linda: Who’s the man in your photo?
Jabz: I have no idea. I didn’t even know he was there until I browsed through the photos.
Linda: Did he photobomb you?
Jabz: Yup. That is exactly what he did. He just decided to be a part of my photo, and the photographer didn’t notice it while he was capturing.
Linda: Haha! That’s funny.
Jabz: I know. I also smiled when I saw it.
“Photobomb” can also be used as a noun or an adjective.
Jabz: There are much funnier photobombed pictures online. (participle adjective)
Linda: Really? I need to see more of these photobombs. (noun / can be used to refer to the picture itself)
Jabz: Some lucky lady had Nicolas Cage as her photobomber. (noun)
Linda: That’s so cool. I think I’m going to try it next time I attend a party.
Jabz: Be careful not to upset anyone.
Linda: Of course. I’ll be careful.