Pony99CA wrote:It's not gravity. Kepler's first law of planetary motion states that orbits are elliptical with the Sun at a focus point. This clearly has the largest body at the center.
I'm about to go really, really nerdy...
A circles is an ellipse in the special case where the two foci are at the same point. If you view this shirt as if the planets are moving in and out of the plane of the shirt, then that would cause the circles to appear squished. As long as the orbits only appear elliptical because of perspective, there's no problem.
However, electrons are quantum mechanical in nature with no definable size or radius. They are more like clouds than billiard balls. For your consideration, I present Wikipedia. So, this is clearly not the model of an atom.
As for the planetary aspect, it just so happens that when solar systems and galaxies form, the conservation of momentum dictates that almost always, you'll find that the object flattens out into a disc. See this great minutephysics YouTube video. It is highly unlikely that you would find the orbits of three planets moving in different planes.
Finally, orbital mechanics shows that planets need to be at different distances from the central star in order to have stable orbits.
So, in summary, this is definitely not an atom, but it might be a highly unusual solar system with circular orbits that due to perspective are squished, with each object orbiting at the same distance from the central star, but in different planes.