Maybe at the exact moment, but generally look at pictures later to spark memories of places they were and things they did. The people who are around when the picture is taken are therefore most likely to want to see it again later.
I guess I don't know about you, but when my wife gets together with a bunch of her friends at a party or event, they snap ridiculous amounts of photos, which they then post on their facebook walls to share with each other. Really, this app just seems to take out the step of sharing on facebook and replace it with sharing with its own network comprised of local people.
Whether that is something people want remains to be seen.