The entire work is amazing, mainly because it construct an entire story without the need of words or even so many actions. Specially is the way you create the atmosphere; the first two looking dark and depressing, yet this last one is not only uplifting, but the almost blurry, overly bright colors made it look as if it was a dream, a miracle happening that defy the very boundaries of it's reality.
Above else, it works because you don't show Pinkie face, allowing the viewer to let himself introduce in the story, allowing those feelings of awe, of surprise, of joy to enter directly into our minds and live vicariously through this image, as if our childhood desires had been also fulfilled.
I don't know if it was on purpose, but the fact that Pinky hair is still straight can send the message that this entire encounter is a form of delusion for her part, which allow for a more dark interpretation of this picture.
Overall, this artwork is very well done. You have a fantastic style to your art, and your attention to detail in lighting is outstanding.
Vision received a 4 for a couple of reasons. You don't have to be an art major to know that Dashie looks happy to have her stuffed animal, and Pinkie's existence in the artwork suggests that she was the creator, which begs a few questions as to the origin of the story and how we got to this moment. However, the picture seems pretty simple; it lacks a bit of depth. Essentially, this is a great-looking drawing, but it doesn't really support a stable story in my imagination.
Originality: I love the idea of Dashie having a stuffed animal version of herself, but the stuffed animal concept seems ripped from Twilight's Smarty Pants. Your rendition of the doll to be from Pinkie and made into a little Rainbow Dash gave you your 3, but the concept itself has been used before. Overall, the picture is original, but only just.
Technique: Where's the beef? Here it is. Technique is my favorite part of critiquing [and generally it's where the real meat of the critique is], because I'm a bit of a stickler for attention to detail and lighting: the more there is, the higher the score. However, detail and lighting aren't the only things I grade this section on; it's also on how well you capture their emotions. Few people realize how difficult it is to capture emotion; anyone can make a smile, but only great artists can make a truly happy character. You've created a very happy character in Rainbow Dash here; not quite perfect, but you can almost feel the happiness in her eyes. Your specific lighting techniques are astoundingly impressive in that they can afford to be less detailed, and still somehow give off so much meaning to the artwork; everything's glowing. One thing I'd improve on in particular, however, is Pinkie's hair and facial features. I was nearly done with a first draft of this critique and had to start over because I realized that the pink hair wasn't another blowing curtain; it was Pinkie. The style you created her hair in seems far too similar to the curtains in the background. The last thing I'd improve on is to make her nose look a bit different; the nose you've given her doesn't really make her look like a pony. I can't quite put my finger on what it's missing, but there's something about that perspective that makes the nose look less like a pony. Aside from Pinkie's hair and nose, though, everything looks spot on. Very, very great work on your technique.
Impact: I don't generally enjoy grading on impact because there's not really much of a way to go into detail about the description; did it resonate with me or did it not? You got a 3.5, because while this isn't the greatest pony image I've ever set my eyes on, it was adorable, and I like PinkieDash all the more because of it.
One more quick thing: I'm a sucker for high-res. If you can post these fantastic artworks in higher resolutions, I'd be ever so grateful.