Zara limited edition slip dress NWT

Gorgeous slip dress with a beautiful ruffled tier at the bottom and a loose corset tie at the back! It's a medium, but it runs small. I would absolutely say this would more properly have been sized as a SMALL and *not* a medium. Has an inner muslin-type dress and a more sheer overdress with the ruffles. Beyond pretty! It's NWT but it came with a small opening at one side (see the final pic) which is about 4" long. It's not a big deal at all and I was going to either close it up myself or live with it, because it's not noticeable, but the unexpected smallness of the dress meant that it didn't drape well on me, anyway. So the dress's unexpectedly small sizing is someone else's gain!