What a shame! Looks like it would have been a lovely blouse.
I've never had this happen from Nordstrom before but it has happened to me from another retailer (non-clothing item). It was one of those pouch envelopes and it had a hole in it, so I suspect my item may have just fallen out.
Even though my empty package was a non-clothing item, I had something different happen with a clothing order that may have evoked similar feelings. I know my clothing item was delivered but the package was stolen. The item I wanted was no longer available so I was never able to order a replacement.