Decorating pews for the ceremony can be difficult. Not all wedding ceremonies are performed in churches, and sometimes churches are the most difficult places to decorate of all. A lot of churches, especially Catholic churches in my experience, do not allow tape on their pews of any kind, so trying to attach some sort of decoration on pews usually ends up with a wrestling match between you and some rubber bands. There are also clips, but those slip off easily, and you don’t want a flower arrangement slipping off as you walk down the aisle in your full-skirted wedding dress.
Above is a picture from a wedding in which I was a bridesmaid a few years ago.