Is gravity 4D?

Imagine our friend living in a two-dimensional world. Here they are standing between two galaxies, which are both radiating light and the gravitational force. In this world, light is confined to two dimensions, but the gravitational pull from the galaxies might spread out in all directions, like an expanding sphere. If their two-dimensional universe were bent or twisted in an unusual way, like this, our friend wouldn't be able to see the light from the galaxies until it travelled all this distance and back to them. The gravity, on the other hand, could traverse higher dimensions, or in this case, across the boundary of the folded-up universe. This might explain the mystery of dark matter, if our own universe was folded up in a similar manner. If gravity could extend into higher dimensions, then we could potentially feel the gravitational effects of a distant galaxy, maybe billions of years before we are actually able to see it.