They're mostly constant. Sometimes you'll see small stylistic differences, but the pattern author should give you a legend of the symbols. Personally, I like them since it's easier to know which stitch of the precious row to work into.
Creativity
It is so fluffy! Is it a typical single crochet amigurumi pattern under the fluff?
I agree with the other commenters - it's definitely an advanced pattern.
One other thing I want to point out is it's tagged with "chart" and the description says:
The pattern, in a diagram form, contains...
There's a chance there's no written pattern, so you'll want to familiarize yourself with crochet symbols and charts before attempting it.
That white eye outline looks like a pair of glasses
Aww. I've never heard of these guys before
Haha
I'm getting "He is....the most interesting bird in the world" vibes
The head to body ratio does seem off. I don't know the background of this kitten, but maybe it has a condition like Hydrocephalus, which can cause an oddly shaped head.
I definitely thought snow camel was going to be a euphemism for moose but nope, that's actually a camel
Fluffy belly!
The bonus pics are great. I enjoyed the cats on the starry cloth and their revenge capes.