I dunno she seems to put a lot of he weight behind it when she does it. It's not just her boobs doing the crushing. Even that aside I'm really not so impressed with it, beyond how bizarre it is, an overly ripe melon is absurdly easy to break, cans fold very easily with little true force, and those boards were pretty weak in my opinion.
I assume they are implants which means she likely doesn't have a lot in the way of sensitivity and I can only imagine how thick the scar tissue would be around those things. As someone with extensive scars I can testify that I feel almost nothing from them and it takes a lot to make me feel any sort of pain as far as they are concerned. I bet if you gave her nipples a good tweaking she would feel it.
Still she got on TV which is more than I've ever done, I just hope she has sense enough to have them remove when she starts to become more advanced in age, before they cause serious health issues.