Continuity mistake: In the Fortress of Solitude while Superman is in recovery, the robot has him doing exercises to build his strength. The shot pans over to show him pushing up on a weight machine. There are several vitals reading patches on his torso with cords hanging from him, except for two additional patches on his stomach that have no cords. It then cuts to a close up of him and suddenly the pointless patches on his stomach vanish. Also the parts he is pushing up against with his hands are instantly significantly smaller.
Picture added by Quantom X