Maybe he'd give Smarty Pants back to her if she would return that lick he gave her when Discord was free. Even if she doesn't get her doll back at least Twilight Sparkle could take comfort in the fact that another pony values it as much as she does.
All that aside, you did a fantastic job on showing how frazzled Twilight was before yet now with pleading eyes and expression. It's hard to tell what else is going on without a full view of Big Macintosh's face: before seeing your text I assumed that he was giving it back to her before she had to face the princess. (It would have been a nice thing to do, but he wasn't around.)
On the most part, this is AWESOME! However, I have one critique: Twilight's leg seems to be thinner than I would expect it to be, comparing it to the (somewhat apparent) size of her body. If you were to redo this, I'd suggest making the part of the leg (that is at the bottom-most part of the painting) a bit thicker. This, however, is just one small part of the whole painting. It is still, as I started out saying, AWESOME!
Thanks, you are right about her leg. This submission was more of a way to keep drawing, not really something original, just a shot from the episode. Translating the 2d to 3d doesn't always work and often requires changes. I guess her leg doesn't make sense at all in 3d.
I suppose there would be some difficulty, yes, but I've seen it done before. ( Sorry if it sounds like I'm calling you a "noob" or something, but I don't know any other way to say it. ) Anyway, this painting still testifies to how good of an artist you are.