Can someone explain what makes a good ledge hang?

I thought it meant how much of a hurtbox is poking up (mostly from the character’s hands) while they hold the ledge. If that’s the case, then most of the human characters seem like they would be considered to have a good ledge hang since their hands are small. I’ve heard commentators say Ganondorf has the best ledge hang and Sephiroth the second best. What makes this so?

Or is a good ledge hang defined by how much of a character’s hurtbox is out and away from the ledge (versus being underneath the ledge and thus more safe)?

Tweak said Sonic has one of, if not the best, ledge hang. I don’t understand this at all based off the two potential definitions of what makes a good ledge hang that I have in mind. His hands poke up and it looks like he still has a pretty big hurtbox that isn’t tucked underneath the stage to keep him safe while he’s hanging off ledge.