Was at Manchester Airport a couple of times recently and really should pay attention to the possibilities!
#1 Classic 'down the middle' shot - works well with the figures to give scale
#2 Interesting abstract quality - would've preferred perspective correction to give horizontal railing along the bottom
#3 My fave with those reflections tho' does need a 'kick up the pants'!
#4 Not too sure of this - think it'd look better without the building on RHS (never mind straight!)
#5 Classic 'down the middle' 2 which might benefit from having someone closer to the camera
#3 Rehashed:
Adjusted levels, curves, saturation, sharpen