I had the same question. You should probably explain a little more in the app's description at the very least.
Like other social media type products, I think people want to see that other people are using it before using it themselves. You don't have any signs of life when opening the app to let the user know if anyone's home. No counter of photos uploaded, no number of "online" users, no stream of incoming pictures.
I guess further down the line it would be nice to know if the images you get are somehow more interesting than just randomly scraping images.google.com. Voting, being either close of far geographically, color similarity, temporal locality. Anything.
I would probably not give up if this version of your app fails to take off. Instead I would be looking for feedback and acting on it. It will probably take a few iterations to prove to users this is a real product that's worth taking seriously.
Could someone post a summary for us Linux users?