Make up ice breaker cards and games that people could pay at the reception before it actually starts. Even games where people go into teams or something and have to find things! It could be fun?
Oh, dear god NO! Forced fun. This is like going to a team-building event at work.
Or even suggest some places near the reception (if central location) that guests can go to near by for coffee or something during the wait. Like if theres a Starbucks or Mcdonalds near by and people want a venture. Or even try and get some discount coupons or codes for various bars near the ceremony so people can get a drink there before they come to the reception. If you ask a local pub or bar, they may put something together for you (just for guests) while your away getting the photographs done.
Yeah, tell 'em, 'The photos are more important than anything. You are just props in our show. Fuck off somewhere and feed yourself, then come back when we call.' SO, SO rude.
OP I hope this helps and trust me see the people who want to be at your wedding will come regardless of the time in between !
They may do so because they feel obligated, but doing this, don't expect them to be happy about it.
Sounds bloody rude.
As for 'Everyone tells us mine was the best wedding', what PyongyangKipperbang said. Give me a break!