Birthday Cupcake

One of my good friends recently had a birthday, and I whipped up this card to honor her special day. I based it on a layout by Mariana Grigsby in this recent Embellish Magazine challenge post. And here's an added bonus:  I'm offering a little prize if you can figure out my layout mistake. While this isn't the best quality photo since I had to use my phone rather than my digital SLR, you should still be able to see the whoopsy if you look closely. (You can click the photo to enlarge.) You have until Saturday at noon CST to post your answer. I'll select a Random.Derek winner from the correct answers. Good luck!

Cardstock/Paper: SU - choc. chip; pixie pink; tempting turquoise; glorious green, more mustard; watercolor paper; Sizzix - shantung texture, silver
Stamps: SU - Crazy for Cupcakes; PTI - Around & About Sentiments
Ink: SO - timber brown
Misc: Bazzill - micro brads; MM - stitched grossgrain; Sizzix Texturz - #20 (Birthdays), SU Backgrounds #1; machine stitching; ScorTape; pop dots