I'm not sure if it's perfect, but her legs might look short because she's wearing a longer shirt than expected.  Looking at it again, I did connect the pants too low because of that, though.  

As for why they're flat, it's because A. faces are hard to get across in such low detail, especially animated, and B. because I'd rather spend the time animating than going over shading.  I consider my animations complete because I set out to make them this sort of flat look.  I've been working on slightly larger sprites lately that have a bit of shading, so I practice there.  

I'll clean this one up and edit the post, plus start thinking about adding full shading to future animations/going back on these ones.  

Noted for the future.

The character's thighs change width from frame to frame. The legs also look rather short; when the legs are far apart, they should probably not be joined at the top, since the pelvis is higher, covered up by the black shirt.

How come you rarely have shadows or dacial details on your animations? Though I'm generally a fan of flat, low-detail styles, yours feel rather unfinished, like they're at the stage where you're working out the animations, rather than filled in and finished.

By the way, you don't need to upload a detail file if your whole piece fits as the preview file. The detail file is only needed if the two are different. PJ will automatically display the smaller file as the main file if that's all there is, and it'll avoid the redundancy of having the same thing twice on the page.