Dianna's on-set "Mompos" dress was from Plenty by Tracy Reese, and is available at Anthropologie for $228. As described on the site, the look features "eyelet-style embroidery" and a "full A-line skirt" (in other words, it's adorable).
Now, if $228 is a little steep in your book, we've got you covered. Check out these slightly different but affordable alternatives:
Denim Flower Crochet Insert Waist Sundress from Top Shop
Similarity: This dress only features embroidery along the waist-line, but the colors are a near-match, and it's quite a bargain (and we're always willing to compromise for that!).
Cost: $70
Flower Embroidered '50s Dress from ASOS
Similarity: If you thought the original look just needed a touch more embroidery, then this is the dress for you.
Cost: $116.55
See how easy it is to get the look? If you're feeling especially bold wear it to Times Square and take part in your own "Glee" re-enactment (okay, maybe we're pushing it now but how fun would that be?!).