The post began: “So, I am really hooked and I’ve watched the entire series many times. And I just spotted this plot hole.”
The viewer went on to explain that if we go back a bit in season 10 to episode 10, Leonard Hofstadter (Johnny Galecki) and Sheldon argue over who will get what in their apartment.
The post continues: “In the first half, Amy and Sheldon bring the painting of Amy and Penny to Leonard and Penny’s apartment.
“At the end of the episode, we see that Penny and Leonard set up the painting in their apartment.