Ours is now darken in the oval and have it scanned. But that just started this year. up until now we had the mechanical booths. you stepped in, pulled the big lever that drew the curtain, pulled down the little levers under the names of your choices (It only allowed one pick per position), then when you pulled the big lever back to get out it registered your votes, and reset the levers for the next voter so no one saw your picks.
No paper, no scanner, one stop, real simple.
Sometimes I think "progress" is a step backwards