Well bloopers rather aren't anything canonical, so rather aren't good source of information about anything. And well previous generation are... well previous. Now we have other world, also with other ponies anathomy. And well on this scene when one of Pinkie's clones shape its head in way like pony's head look in G1(or maybe some other previous generation? I'm not sure, they all has very similar graphic style and i only seen some fragments of them, very long time ago...)... and then wass clearly seenable(by comparing size of the head with rest of body) that ponies in previous generation really was bigger(well if we look at this like that then now name "My LITTLE pony" really get its reason).And yes they are cuter in smaller size, but what even more important they look just natural in the size You draw her - I think is clearly seenable. When they are bigger it doesn't look naturally look for example at this picture: vector-brony.deviantart.com/ar… in it proportion of ponies and humans are like in previous generation, ponies are not bigger than humans, but still it looks really weird.In one word(or rather sentence) - I still think You get ponies size right in this picture.