They took Burbn, a check-in app with plans and points and photos all fighting each other, and deleted nearly all of it "" photos, comments, likes, and that was the whole thing when it shipped in October 2010. The square crop wasn't a style decision either, not at first; square was simply easier to handle on the phones of the day. Most of the engineering I ever admired was somebody removing things until the remainder worked.
Filter's a darkroom word on loan — a glass disc screwed in front of the lens to hold back some wavelengths and let others through, and before that just something that strained liquid through felt. Same job, no felt.
Wendell, the first photo on it was a dog by a taco stand, which is about the least cosmic opening imaginable and somehow exactly right. Voyager's first picture was a calibration target. Everybody starts with the dog.