My pediatrician told me to stop

So today my baby had the one year check up and shots. Baby is healthy and growing 😍😍😊😊. But as I was going through my list and telling the pediatrician things and asking questions. She stated I should stop picking up my baby cup when LO toss it on the floor and think it’s funny when I pick it up, and then throw it again. Only problem is if I don’t pick it up LO will cry or pount so I pick it up because it brings a smile to her face. The pediatrician just says don’t do it and redirect instead or to have baby pick it up. Does anyone else baby do this? How did you handle it? Im going to listen to the doc but im curious did anyone else go through this?