The zig-zag meander suggests water, and the curving shapes underneath look like horns of plenty.
And then there's this extraordinary figure.
A big-bellied woman, legs splayed, with a leafy sprig coming out of her vulva. In her right hand she holds a sickle. Her face is blank. Her headdress has little points suggesting either horns or a crown. The meander begins at the tip of her sickle and terminates in her cupped left hand.
That's what I think we're seeing anyway. The carving is so rough there may be other interpretations. Traces of paint remain.
Who is she- A river goddess? A fertility goddess? St Mary Magdalene? I really don't know.