Shortening is used for Chicago style deep-dish pizzas while oil is used for Pizza Hut style pizzas. The biggest benefit to using a solid fat in the pan such as margarine, butter, shortening (Crisco/Butter Flavored Crisco, my personal favorite too) is that the dough really clings to the stuff making it a snap to pull the dough up the sides of the pan without the need to continually chase the dough pulling it back up after it slides back down into the bottom of the pan. Texturally, oil in the pan gives the finished crust an oily/fried appearance and feel while the solid fats impart a dry appearance to the crust , much like what we normally see on the sides and bottom of a loaf of store bought white pan bread. To apply the solid fat to the pan you can either brush or wipe it in using a paper towel or you can melt it and brush it in for a more uniform application. In a commercial setting we almost always melt or at least soften the fat and then brush it into the pans, but when I make deep-dish pizzas at home I always apply it right from the can using a piece of paper towel to wipe it around in the pan, makes clean up a little easier, just toss the paper towel in the trash, no need to wash the fat out of a pastry brush.
By the way, that is one VERY GOOD looking pizza!
Tom Lehmann/The Dough Doctor