A fake feeling of nostalgia for something old you didn't actually experience - like Instagram filters and throwback branding from before you could actually walk.
The 20-year old said the X-Pro II filter in Instagram really gave him fauxstalgia for the good old days back in the 1970's.
Fauxstalgia is sometimes used by folks who weren't born at the time to hark back about their experiences in the second world war, or used to remember a thing that didn't even happen such as the world before migration.
Karen aged 50: "Yes it reminds me how good it was in WWII when we didn't have transgendereds"
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"