the delimitation is not for data (that is closed over like any normal closure), it's for control. when you apply a reified delimited continuation as a function

the delimitation is not for data (that is closed over like any normal closure), it's for control. when you apply a reified delimited continuation as a function it returns a value to that call site, to do the same with a traditional continuation you need to apply the reified continuation using call-cc, and it needs to know what to do with this continuation.