When Tam offers to trade lunch with Sheldon, Sheldon is holding his sandwich. However, in the next shot, the sandwich is back in the wrapping paper without Sheldon putting it in.
In voiceover, Sheldon mentions the character Cyclops shoots laser beams from his eyes. The beams Cyclops fires from his eyes are concussive blasts (called optic blasts in the X-Men comics) and not lasers. Lasers burn and vaporize what they strike. Cyclops' optic blasts hit like a sledgehammer.
Sheldon mentions, "A Cyclops shoots laser beams from his eyes." Cyclops have only one eye.
The series is set in the late 1980s. However, the comic book Sheldon reads is from August 1980, and the comics on display in the comic book store are from the early 1980s to the 1990s.
According to Sheldon's own principles about not allowing different foods to touch each other on his plate, Meemaw's dinner shake of pork chop, gravy, and broccoli would be absolutely abhorrent to him.