The x-y plane at various z values

First of all, since the fixed target holder is at 210 cm < z < 212 cm  and a few cm distance, I checked this z range at both sides:

Nothing asymmetric seems to be there. Just to be sure, I checked the x-y plane at various z values, at 80 cm intervals:

Zoom 0: x,y = -10...10 cm

Zoom 1: x,y = -100...100 cm

Zoom 2: x,y = -450...450 cm