Hi makesunshine,
Welcome to the Mattress Forum! 
Congratulation on your new BB Signature mattress! :cheer: I’m happy that your initial impression is a positive one.
Point elasticity refers to the ability of the material (foam layer) to conform to the curves of the body with minimal disturbance/pull of the areas of the foam layer around it, so it contours quite finely where mass is applied. A smaller area can compress and contour with less impact upon or resistance from the areas of the foam surrounding the mass being applied. Memory foam, latex, and many of the newer plush “high performance” polyfoams tend to be quite point elastic.
Phoenix