The sack gradually is meant to shrink back to be almost flush with the skin. Sometimes it fills with fluid if they've had a good slurp at it and needs to be drained, some times it just naturally doesn't shrink back as much - which would be the reason we had to have three flipping followups on woofbags since his didn't "deflate" as much as expected (vet OKed him though and just chalked him down as one of the rarer cases with a defiant scrotum)!
They don't so much scoop as squeeze the balls from the scrotum til they pop out through the incision. There will be some swelling for a while but the scrotum will eventually shrink until it practically disappears.
As long as it's not hot to the touch or weeping or anything (as these are signs of infection) then I wouldn't be worried.