let's collect bromides

Last week, A.W.A.D's theme was words from chemistry, and the first word of the series was "bromide":
A Stephen Ross wrote A.W.A.D:

I thought you might be amused by these packages I saw on display in convenience stores in Japan back in 2003:

I believe that the packages contain photo cards of the ever-renewed teen-pop group "Morning Musume" (morning daughter). I do not understand the "Let's collect Bromides!" caption, neither does my Japanese wife. Yet another of the many mysteries of Japan.

But the mystery was immediately solved by a Joe Presley, who seems to have been unaware of the mystery he was solving:

In Japanese, a "buromaido", is a photo of a celebrity. It comes from the days when a silver bromide emulsion was used for photography.