Hey, CityTraveller, and welcome to the forum!

I had missed that you were in Chicago. If so, is that bike at Nearly New by any chance? If so, they are straight shooters by all accounts. I've only been there a couple of times, to buy a part or two, and everything looked to be set up well and fairly priced.

From that one picture it does look like the bike most likely has alloy rims.

Steel rims will be very shiny (or once were). They are much less desirable because they are much heavier than alloy, and more importantly because when they get wet the braking surface is like a mirror, and it's very hard for the brake pads to grab them. This means greater braking distance compared to alloy rims. If you know what to look for it'll be fairly obvious, or seller should tell you. If the bike has steel rims, you might use that as a bargaining point and try to get them to either replace them with alloys or discount the price. Used alloy wheelsets are not very expensive.

This doesn't mean that bikes with steel rims are death traps! You can ride them just fine, but need to be a bit more aware of braking distance. On a bike like that your pace is probably going to be leisurely anyway. For one thing, everyone you pass by is going to want to stop and ask you about your cool bike.