It's a museum, a holy relic, a monument in time, a last standing, honest to goodness Isaly's. This place is one of the last 3 remaining diners from the iconic chain of restaurants. It was the focus of the PBS special, Sandwiches You Will Love.
If you are not a Pittsburgher, you may not understand or appreciate this place. The reason it does not change or innovative is because it is a genuine piece of nostalgia and a rather meaningful part of the lives of people who grew up here.