Cam is a picture taken by Aidou for this album, most of which are unpublished pictures. The front of Cam is mostly written by Aidou, and there are signatures and so on. So many fans collect it. Cam is of no practical use, because beauty or handsomeness is more about love for beans.
Small cards are expensive because they are never shipped back to the album, and an album has only two small cards, plus the postage required to send them back, so they are almost naked cards, so buying cards is equivalent to buying a special offer. But under normal circumstances, small cards will not be issued separately, and they are a set. See the photo album configuration for details.
One is to deal with the small cards in the group station, and the other is to meet the requirements of many fans to collect cards (after all, the small cards in the big station must be removed from the album, which is highly reliable and it is easy to buy fakes outside), so as to improve the enthusiasm of fans to buy bricks later.