You would do well to post this with /r/askanthropology. The only thing anyone can provide, however, are theories for this and other so-called "Venus statues." In general, Upper Paleolithic art - whether in the walls of caves or mobile, depict humans with stylized faces. Sometimes the bodies are accurately depicted, but with only a few exceptions the faces are obscured. This was not for want of skill as artists since animals are typically depicted with extreme accuracy. So the manner in which people are depicted is a curiosity, but aside from being descriptive, explanation is not possible.

The Venus statues are often corpulent, suggesting this was either some sort of ideal, the image of a goddess, or a device intended to bring opulent times (or all of that). But these are only theories - against your protests! Since this is from a prehistoric period, there are no written documents to inform us as to what might be the inspiration for these statues. All that is or ever will be possible (short of time travel) are theories.