The word “photobomb” seems to be quite “in fashion” these days. Basically, it means a photo
where someone who is not supposed to be in the picture shows up in the photo, makes a face,
or does something to mess up the original composition.

Here I finally get my nephew Jett aka "PoPo" to sit still for a snapshot when
Zoe pops up from behind and makes an “angry face” :-)