Sometimes delis can surprise you. A lot are interchangeable. But fairly often, proud owners do a little something decor- or merchandise-wise to set their business apart.
I happened on with narrow deli on Lexington on the Upper East Side that has an entire Midtown Manhattan skyline made out of tile on the wall. It's impossible to take the whole thing in at once (let alone photograph it) because much of it is blocked by the salad bar. Because of this, I doubt that many of the deli customers actually notice it.