juxtaposting
When sitting near or next to someone and posting on their Facebook wall. This sometimes happens at cafes or in school computer labs, even among roommates. (comes from the word juxtapositioning)
I was creepin' on my roommate's page while he was next to me and I couldn't resist juxtaposting on his wall.
juxtapost
When two dissimilar social media posts follow one-another and they make an enhanced meaning together
The post on "The Feeling of Being Watched " was followed by a picture of a big-eyed Flying Lemur, the juxtapost was hilarious