Why won't my icon show up as full size on the new Chrome Web Store?

I have a published extension in the Chrome Web Store. Last night, the web store got an updated look, and now my icon appears really small, inside of a jigsaw puzzle piece. I followed the instructions, and uploaded a 128, 48, and 16. All three image files are PNG. My extension is the only one I have seen that is displaying in this way. What did I do wrong?

What happened to my Chrome extensions?

If you are using extensions in your Google Chrome web browser, such as Snap & Read, Co:Writer, Kurzweil or Read&Write, you may have come back from summer break and can't find them in your Chrome browser. Until recently you turned on/off your extensions in Google's Chrome web browser by going into Settings > Extensions.

It's a feature of the store, not a problem with your listing.

All extensions now show their icon inside of a jigsaw puzzle piece; "apps" are free of it.