When Martin Senescu answers the couple, "Perhaps not young man..." The left most sailor (dark hair) is looking to his right, arms uncrossed, by his side. As Martin continues to speak (no break) and the camera angle changes, the sailor is now looking up and to his left, arms crossed with his left chin touching his chin.
When they first go into Murderers' Row, the light shines on the "wax figure" with the hatchet, and you can see him blink.
As Balsam's character says, "The museum can't be held responsible..." the "wax figure" on the right can be seen to swallow.
When Emma comes in from shopping and starts to unload the groceries, the egg carton is obviously empty.
There are minor movements seen from the wax figures throughout the show i.e., Landru's clothing is moving due to his breathing. This is clearly visible when he's first introduced in the museum.