a group of people walking across an airport
how many people are in the group
over 30 people in the picture there is no 1 group
so it is just a crowded airport
more like a subway but yes
can you see the tracks
no
is there a train
no
are the people on platform
no
what makes you think this is a subway
the building and the blue portals
are there any clocks visible
yes but blurred by the light
do any of the people have luggage
no
are there any signs visible
yes a few
can you see an arrival departure board
no