I opened it, and most of the screen looked like a big, roundish black blob of ink, centred on the fold, on top of the Android animations working perfectly underneath, but only visible at the edges. I was impressed that the rest of the screen around worked perfectly, but it was unusuable due to the size of the black blob.
Something had broken at or near the fold while it was on display.
All other devices were in great condition; it was a well-maintained store.