If you think about it, it takes a lot of strength to lean forward like this when you have so much weight in front like her, yet she will straighten up and walk around. 
And for a number of years, from a physical therapy standpoint, she has been doing it correctly by incorporating bending at the knees, which likely came naturally secondary to balance. As we have seen in many videos, even small tilts off center do challenge Beshine's balance, which accounts for her hesitation and careful stepping downward, even when it may only be a few inches. This is an example from 2016, when her Denmark vacation resulted in a number of videos where you can spot her balance being challenged. It seems the most profound is when she is bent forward and straightens up too quickly, the weight and momentum of her boobs almost causing her to fall backwards.
Yeah, I've seen on her videos how carefully she walks around, goes up the stairs, and walks in the forest. After all, if you or I were carrying 80 pounds sacks of stuff in front of us, we would have to be careful also. The human body naturally is not balanced for that, so we have to adapt and think hard what we are doing.
She handles going up stairs pretty well, no doubt because her legs are so strong, not only from her elliptical, but also from all the bending at the knee she has to do for so many things, like your earlier picture demonstrates. I have to imagine that even around the house, in the course of a day, she feels that slight imbalance a few times, just from the inadvertent slight tilt when turning or reaching. Just gets her excited for that split second.
The past few days on OF, Beshine is shown lying down. Yesterday and the day before, she shows two angles of what she look like when on breast is lying on the floor, the full extent of her turning to that side leaves the upper breast, though resting against the lower, still resting vertically on her chest. That is quite a lot of weight every night, however, today's picture shows what happens when she is lying on a sofa and allowing her breasts to extend past the cushion. Though her body is still on the sofa, her right breast is so wide that her sideboob is nearly touching the floor while her left breast extends high above. All this while she uses her left arm to grip the arm of the sofa to prevent her boob weight from pulling her entirely over the edge. Not a position she would seek to hold for long considering the weight.