Why is there a gap between the plates?
Spinlock collars. Either that was working up to a max and she didn't want to strip the bar or they didn't have enough #45 Olympic plates to lift with. The one set of #45s brings it up to competition height, then you add your #35s, 25s, 10s, etc.... Or someone was doing cleans or presses beforehand, and she didn't want to strip the bar.
Lots of oddness with plates back before Olympic plates got cheap and foundries got tighter on tolerances.