This manufacturer mis-assembly (a "bridge" support that is too short that mounts the meter jaws close to the front of the enclosure) looks like, if one shoves a meter movement into the meter jaws, the short bridge doesn't push back, 'cause its not against the back of the enclosure. The pressure of pushing the meter into it's jaws bends the bus bars coming from the line lugs beneath the jaws, and the bolted upper end of those bus bars might, in fact touch the enclosure.
Looks like one could even get a 240 V short through the pan.