This is obviously a potent anti-predator strategy. Nobody wants to eat poop. So this spider can go about her bidness without worrying too much about getting picked off.
Observing her for quite awhile, it became apparent to me that this is a spider who is highly concerned for her safety. With such a big heavy abdomen, she would need to be careful about falling like a stone on a hard surface. Everywhere she crept, and she didn't creep far, she laid down silk, guywires and safety lassos to catch her should she lose her footing. And when she eventually did, there she hung, safe, with my palm as backup. She was cool and heavy as a quarter.