A Shrek 4D promo photo is up on Universal Studios Hollywood's site. It's not much, but it provides a fairly decent picture (if a bit cheap) of what the movie should turn out like:
http://themeparks.universalstudios.com/hollywood/website/shrek.html
Fortunately the attraction should rise above it's press material.
http://themeparks.universalstudios.com/hollywood/website/shrek.html
Fortunately the attraction should rise above it's press material.
