As she explained on her app

"I definitely had to share my tape secret with you guys!! It's my secret trick to have perfect cleavage in photos. You tape them up so they are super lifted. It takes a little work but trust me it's all worth it LOL. I've used everything from duct tape to packing tape to masking tape and I think that the best I found is gaffer's tape. It sticks the best! Make sure you don't have any lotion or oils on when you're lifting your boobs up with the tape. Just brace yourself for when it's time to take it off LOL."