Cartoons still follow proportions.
Sure, you can look at Ren and Stimpy and go, "Those aren't proportionate at all! They're nothing like the REAL proportions of a REAL chihuahua and large cat, resectively", but if you rub your braincells together just a little bit harder, you'd quickly realize they are proportionate. To themselves. If they weren't, they'd look like Rory's art.
If you've ever read an art book, you'd know something extremely important to this discussion, and criticizing Rory's art: Proportions are never described as exact measurements. Humans' eyes aren't 3 centimetres apart, exactly. Instead, they're "about an eye's width" apart. As in, the width of the
individual person's eye.
This is why cartoons work in the first place. Because even the Fairy Odd Parents' fingers end at their mid-thighs, and even Jessica Rabbit's shoulders and hips are 1:1. Some cartoons have more conservative, realistic, "correct" proportions, like Disney's 2D fare, or low-budget eighties cartoons. But most don't. How?
Because they
know the rules, and when to break them.
You can make a cartoon character with arms that are too long for their legs, or a head that's too big for their body, or with 1 cm eyes set 10cm apart. But you can't do all of that at once, because then it's just a bunch of random shapes stapled onto eachother. There's no middle grounds that the shapes can meet at. The character is rendered charmless, inconsistant, and ugly, on top of being a pain in the arse for anyone else to try and draw. All because they have
no proportion, so no aspects of the design have anything to do with eachother, and nothing to sensibly connect and balance them.
That is what proportion is. Not how "realistic" the skeletons are.
That is what Rory lacks.