Oh hey, they're a lot bigger than other kpop girl groups.
Then they came back later, much lighter.
Well, guess what, everyone: They're back again!
That's cool. Wait ... something's different about you, Piggy Dolls ...
Oh yeah, and they're coming back as three completely different, skinny girls.
If we look at this mathematically:
Gimmick group - gimmick - all original members = A DIFFERENT FUCKING GROUP
Yes, apparently, three different girls who don't follow the group's namesake image are being referred to as the group Piggy Dolls. I'm assuming this is a less than ingenious way of getting these poor new girls noticed in the ever-expanding sea of nameless rookies.
So here's a question for everybody: How much can a group change (lineup, concept, etc.) while still being allowed to use its original name?