I don't have a lot of confidence in my own understanding of relativity, gravity, etc., but I think you're taking the analogy too literally. In spacetime the obj

I don't have a lot of confidence in my own understanding of relativity, gravity, etc., but I think you're taking the analogy too literally. In spacetime the object isn't warping the 'surface' because of something pulling on it, and the demonstration is not about explaining why matter warps spacetime, only demonstrating the effects of that warping.