Stephanie wants to get her ears pierced. However, in the beginning of the first and second seasons, it is noticeable that Stephanie's ears are already pierced.
When Stephanie showed off her new sunglasses to the two Jennifers, they told her they were out of style, so Stephanie flung them behind her, and they landed on her nightstand. In the next shot, the sunglasses were on her bed.
When the twins are getting their haircut Jasper says he graduated class of 37 Jesse then replied they did not have hair dryers in 37. The hair dryer was actually invented in the 1920s.