A few things I want to point out:



Fluttershy has a weird body shape. Her front left hoof looks like it is elongated. You shaded her mane and tail too dark, it looks like they are actually black. The distance from her to the cottage gives the feeling that she is as tall as the door, which makes her height 1/3 of the house, in other words she is too big comparing to her cottage.



The bridge's perspective is not consistent with the road, it feels as if the bridge is only 5 inches wide.



The cello's style is completely inconsistent with the rest of the picture, and - I know this sounds harsh - it looks like a bad case of photoshop.