According to the link to the picture of the invitation card posted by Gert-Jan in the initial post of this thread, I understand that the dresscode of the pre-wedding reception is white tie for the gentlemen - and probably long evening gowns for ladies. But does it necessarily imply that ladies are supposed to wear tiaras? (I would love it, of course, but I do not really expect it...)
Just as a bonus, a few pictures of Queen Geraldine's floral tiara, which was sold at auction a few months ago - just so lovely, it would have been a perfect bridal tiara!