When I think about what makes for a great photobomb, I believe the following things are needed…
1. A main subject or subjects — photobombee(s) — in funny/interesting/ridiculous situations. Say, a group of Americans posing outside of a McDonald’s in North Korea. Or, say, a horse stuck in a fence.
2. A photobomber atypical of your average photobomber, like, say, a cow.
3. A photobomber atypical of your average photobomber bearing a ridiculous facial expression, like, say, a cow laughing at a horse stuck in a fence.
The photobomb here has all of these elements. Toss in the fact that the photobomber and photobombee are both farm animals and you have what I consider to be the greatest photobomb of all-time. Paris Hilton with the oral sexing kangaroos is a close second.