Quite an intense looking trio here in their whites surrounded by white tiled walls. Definitely it is an oven they are feeding this long tray into, but I am not entirely certain what is on that tray. The one at center looks to be holding the substance of whatever they are firing in his hands, rolled into balls. Dough? Clay? Looks more industrial than edible to me--and their pants are plenty stained. Whatever the case, quite a striking image I think, including for its dissolution into a cloud of white at left. 

5 1/2" x 3 1/2". General wear, a few small corner creases, a little soiling and toning around the border, blank postcard back. Found in Tennessee.