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!).
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.
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?!).