This is a customer discussion site, and B&N only rarely makes any sort of official appearance here. You'll need to follow up with B&N directly to get any official answer. It sounds like you just received the device, so you shouldn't have any problem returning it if you're not happy.
I agree with you that the web page images show a deceptively clear image. Is your device a NST glow, or the basic NST without backlight?
The background on my NSTs (not glow) are not white, but are a very light gray hue. In terms of actual readability, it's just like a paper book by design. It does require ambient light. I actually prefer it not be bright white to avoid eye strain. I certainly don't have to stand outside to read it though. Perhaps you have a dud?
Here's an image I've adjusted to more closely show what mine looks like:
Here's a closeup of one of my actual devices:
I'd suggest you give it a chance by actually reading on it rather than comparing images. The NST gets high marks for usability, including screen clarity (readability) under a variety of lighting conditions short of darkness. It is not a great image viewing device. If you still don't like it, return it. You might find a Kindle Paperwhite more to your liking. If low-light conditions are the problem, check out the NSTG (glow) model, though be aware the background is decidedly blueish. See if you can compare units side-by-side at a local shop before purchasing.
Good luck, and I hope you find a reader to your liking.