It's not uncommon for toy camera viewfinders to underestimate the field of view - the Vivitar Ultra Wide and Slim was definitely guilty of this. But the Double Dip takes a bit of getting used to. The viewfinder view is quite 'zoomed in' but the lens is roughly 35mm, so you get quite a lot more on film than you see through the viewfinder. Here are some examples, the centre area is very roughly what I saw through the finder.
This can make for some interesting compositions - see Karl Lagerfeld in the picture below (I can't remember seeing him at all whilst I was taking this). It means you'll always capture what's in front of you, sometimes a bit more than you wanted, but sometimes capturing something great by accident.
I'm tending to think of the finder view as the centre rectangle in a grid of 3x3, that's helping me get to grips with the quirky nature of the DD viewfinder...
Am looking forward to seeing what people come up with - if you've shot any Double Dip rolls then don't forget to upload them to the DD flickr pool.