A group of people stand near and on a large black square on the ground with some yellow writing on it.
a group of people wait
We don't know for sure why they are standing near and on this square.  It is not 100% inferrable that they are waiting. (that they wait).
The group of people in the first sentence could be traveling, or chatting, there is nothing to imply that they wait.
just because they are standing don't mean they have to wait