Isn't this also called "Arcball rotation"? The biggest advantage over the naïve implementation is no un-intuitive "sideways" rotation after a few sequences of rotation.
The important thing in this demo is that his code reduces to arcball-like rotation in the globe projection, but works on arbitrary map projections. Notice how the interaction works for Eisenlohr's projection in the same way as the globe, but the behavior must be different, of course, since the projections are so unlike each other.
I've heard "trackball rotation" but yep, you're spot on.
To give an example, rotate both the unimproved and improved globes so you're facing Antarctica dead on. Then try dragging left and right. The improved is far more intuitive to me at this point.
