Just different configurations. Perhaps plexy glass between the machines. It might help with second hand smoke too.
I am a non-smoker, my mother was a millitant smoker, so I never made much of a fuss.
Unless I get a rude person blowing smoke into your face. The in between shields wouldn't eliminate second hand smoke (kind of like a no-peeing section in a pool) but it would help with direct exposure.
Rather than a wall of side by side machines you put them into pods of 5 (pentagon shaped) so people are all faced in different directions.