Bah, Pinkie looked sexier on the miniature in Watch Alerts

The concept of this piece is very nicely chosen - combining Pinkie's actual form with the human one gives a great homage to the general, wacky vibe the party pony always gives out. The seemingly simple background is also a good nod to her personality, leaving a very clear image before the recipant.

The most troublesome part to grade AKA "originality" is (surprisingly for me, having wrote several critiques by now) actually quite easily determined this time around - while, per usual, the scene itself is familiar, with the party cannon being overused, it adds a unique twist with the two Pinkies playing in tandem. None of them is presented out of the ordinary, but they work quite well, making the well-known idea come to life... in bright, new colors, so to speak.

The style is not uncommon, but it gets the job done - smooth, bright lines compliment the character(s) splendidly, while the detail on human Pinkie is quite eye-catching.
One issue that is brought to mind is the overall vibe the human Pinkie gives away; from the neck up, she definately makes the impression of being cute, but as you travel up her legs, sometime along the way you get a feel that she was supposed to turn out "sexy". This leaves an unsettling notion that you couldn't decide which road to take with the party pony's humanoid avatar. It could be the effect of her height as, by comparisson to the pony Pinkie in the cannon, her human self seems very tall, having surprisingly long legs.
But, even so, both characters turned out nicely, managing to keep the characterization of Pinkie in tact.

The impact is certainly strong - the bright colors literally smack you in the face as you gaze upon this pic, while the balloons and confetti sets teh recipant in a joyful mood, nicely supporting the duo out front.
You can almost see Pinkie being shot out forward, her expression and pose indicating what's about to happen. The viewer practicularly expects that he'll see the party pony soaring through this piece in a moment. Very suggestive.
The human Pinkie does not remain passive to that with her sugar-rushed expression and the general "happy-go-lucky" attitude, that nearly beams from her body. Her hair style furthers that effect, making the recipant want to join in the fun.
The simple style doesn't divert from the happenings in the pic, allowing one to suck in the delight, which spreads throughout the work, making the viewer participate in the endeavour, thus making him more invested.

Overall it's a very compelling piece; modest but strikingly adequate... to some extend, alluring even... bringing the viewer in with its simplicity.