Ah, I see there's a bit of a misunderstanding.Yes, so I think the short time period between images for the first one explains why you got that time lapse look. There was not enough movement of the extra people to end up with blank spaces for averaging. When you use a longer time frame, more of the background becomes visible over time and the people get erased out because it's evident they are moving throughout.
With the street crossing picture I was actually aiming to get a motion blur effect. I wanted to keep the persons visible, just smeared out - hence the burst shot.