The Come & Go (Open House) Shower: Is it a Good Time or a Street Crime?

I received a rather lovely bridal shower invitation. It’s on a Saturday from 2-4 PM. It says Come and Go. The mother of the groom told me it means it’s an Open House and you can come when ever you want and leave whenever you want.

What do you make of this kind of shower? I have never heard of this. I am feeling they don’t really want to get to know me. Just bring a gift — have a cookie, toss back some punch and leave. No getting to know the bride. What do you think of this kind of shower? I feel all I want to do is send a gift through the mail and take a pass on the drive and the cookies.
— Marsha