There are two racks side-by-side, and each rack is a double-decker.
That adds up to 28 parking slots, plus room for one bike on each side to lock to an upright, for a total of 30 spots in a relatively small space.
You roll your front tire up onto one of the built-in ramps and roll it up and through the wheel-grabber posts at the back. It looks like folks lock in a variety of ways: around the wheel-grabber bars with a cable; around the horizontal cross-bar with a long cable; and possibly to the small metal loops at the sidewalk side of the racks. Looks like u-locks would be a problem if the two spots on either side are taken.
When I took the photos (two different days) there weren't any bikes parked on the 2nd level, but I know I've seen some up there before. If it were me, I probably couldn't lift my bike up that high.
It's great to see 30 covered bike parking spots so close to the main entrance of a business. I applaud their creativity for really packing them in there. Obviously some folks can utilize the upper deck even if not everyone can, so overall that's a good thing.