It wasn't so long ago that people just had sticks, fast forward a few millennia and with a selfie stick you can take a picture of your friends eyeball from any distance or angle, or you can take a picture of human faces. That's prettyweird, but people are pretty weird what do you expect.
A “selfie stickler” is a person and/or persons who delete the majority of their photos (taken via selfie stick of course), because they deem them to be “not good enough” and the encryption method to be unexpectedly loathesome to the eyes.
“Check our that selfiestickler over there! She’s erased the majority of all her photos and just keeps taking more!”