I'm not disagreeing with you, cuz I don't know, but wikipedia says:

A Philadelphia roll is a makizushi (also classified as a kawarizushi)[1] type of sushi generally made with smoked (or sometimes raw) salmon, cream cheese, and cucumber, with the rice on the outside (uramaki).[2] It is sometimes made with imitation crab instead of salmon, but can be found to include other ingredients, such as other types of fish,[3] cucumber,[4] scallions,[5] and sesame seed. Like many Western-inspired sushi rolls, its design and name are modified to target an American market, which includes putting the rice on the outside, and the nori in the inside (inside-out sushi) to appeal to western aesthetics.[6][7]