Ekilby/Flickr. Picnic shoulder is a cut of pork that comes, as you might expect, from the shoulder area of the pig. But then, so too do cuts labeled pork butt (strange but true!).f a recipe calls for one, you can use the other. Picnic shoulder and pork shoulder are the same (with slight variations in how they are cut in different parts of the country) and one can be substituted for the other in recipes without worry.