Bloopy 10 days
If you click a piece card in your collection it'll show you question marks for all the pieces in that set you don't have yet. If you happen to have collected the whole set, then clicking it will remove those individual pieces from your cards and replace them with the newly earned combined (multi-part) card. Note there are some sets with multi-part cards not made of pieces: you can earn them simply by looking at them in the Gallery if you have the related cards.
If you click a piece card in your collection it'll show you question marks for all the pieces in that set you don't have yet. If you happen to have collected the whole set, then clicking it will remove those individual pieces from your cards and replace them with the newly earned combined (multi-part) card. Note there are some sets with multi-part cards not made of pieces: you can earn them simply by looking at them in the Gallery if you have the related cards.