There was registry information in the invitation, so they are expecting gift.
The event is at a place I did not recognize, so I do not know if it's a hall or a spa, but definitely not in someone's home. There was zero information about cost/expectations/etc.
If this was for a traditional wedding, I would be confused, but would just accept or decline upon further information.
Some of you seem to think I'm to rigid, but I thought shower guests were supposed to be invited to a wedding. AT least, that's what I've read on every bridal etiquette site. This is not a destination wedding I cannot attend, I am being told I am NOT invited and they MIGHT choose to have a local reception later. I equate this to an elopement - part of that choice is giving up some of the trappings of a traditional wedding. It just seems convenient to me - you don't want to host others for your wedding, but you still want to be showered with gifts.
ETA - if this was a spa day for the bride to spend time getting pampers with the women in her life, I would think it was a fabulous idea. It's the shower addition that doesn't sit well with me, especially since I had to find out through back channels that a wedding invite would not be forthcoming. I would have assumed it was based on the shower invite.