I’m not sure what this is. My mom came back from Chinatown with a bunch of these enormous things on a huge shell. It’s some combination of scallops and oyster. The orange sack is the oyster like part. It looks like a sac of something, but it’s actually solid when bitten into. The big white part is the scallop part. There is also a spirally thingy on the side. Not sure if you can see it from the picture. That part is more chewy than anything else.
Bottom line is that you’d enjoy this mutated “scallop-ster” if you’re a fan of raw seafood. Mine was cooked with stuff on it though. That stuff is to flavor the dish and to ensure it doesn’t tastes too fishy. Whatever, I prefer my seafood battered and deep fried.