Lexie begins decorating George's locker and sticks a "Congratulations George" sign to the top of the cupboard. She then turns to speak to the group and in the wide shot, the sign is gone. Seconds later, it is back where she originally placed it.
Christina asks if she can keep one of the disease kidneys, that wouldn't be possible for her to do. When they do a kidney transplant, the diseased kidneys are not removed. The new kidney is placed in the lower abdomen and unless the native kidneys are causing a problem, such as kidney cancer or polycystic disease, the kidney stay in the back.