What are the filming mistakes that you never noticed in Friends?

"Friends" is filled with subtle filming mistakes that often go unnoticed. For instance, in several episodes, continuity errors occur with props, such as coffee cups changing positions between shots. Additionally, character outfits sometimes appear inconsistent, with characters wearing different clothing in the same scene. Another common mistake is the presence of crew members or equipment reflected in mirrors or Windows, which can be spotted if you're looking closely.