Drastically varying pet sizes?

So I've been notizing this quite a lot lately and the two people I asked ingame had no answer, so here we are. What does define the pet size? As you can see on the screenshot both my pet and the tortoise in the distance are tiny compared to the blood elves cat.

https://imgur.com/a/ONhlk3J

Could someone explain to me how his cat is so much bigger? At first I thought it applies to level 80 pets because the devilsaur and wolf I saw for example were 80, however both this guy and his pet are only level 58.

Link to the image here in case the embedding doesn't work.

They scale with level.
Mariav is lvl 58, you are lvl 20, and the 3rd hunter seems low level as well.

I read that level scaling is miniscule so I thought that couldn't be it. Thanks for the clarification.