Taking photos of your ballot is actually illegal in my state. (MS) Presumably for this very reason.
Sure, but if the ballot booth provides real privacy... it's not hard to do. It's also a common method of proving you voted a certain way in order to sell your vote.
Or hey, you can just peer over their shoulder:
This morning when I voted I was surprised that it was hardly a "booth". It had sides to the screen to attempt to block it from view, but it you turn your head you could see the screen next to you - and their screen.
The system saves a ton of money and time, and we have record numbers of voters in Oregon this year.