With the two gents comfortable without topcoats, it would seem the automobile has not been running prior to this photo being made --- the thermostat controlled radiator shutters are in a closed configuration. (A touted feature by Columbia.)

Looks like a support for the top framework when the top is folded down. Body curves in and the top braces are outside the body line.

Izzy and Moe, on the verge of stardom?

You sure about the motive power? I see a wind-up key!

Edit: Actually, what is that thing?

Built by Columbia Motors, not related to the Columbia Motor Car Company that produced its own Columbia car from 1899-1910; I wonder how the trademark lawyers handled that?

The earlier company had some connection to the famous Columbia bicycles (still made, I believe), in that both were originally part of A.A. Pope's Pope Manufacturing Company. The later Columbia's name was apparently just another attempt to "wrap the brand in the flag."