Which side is the mouth piece?

i'd probably say the long, thinner side, the top side in your pix, is the mouth piece..

 

yeah, i don't really see any significant difference in which side one was to use, it's a steam roller after all, and it looks like the bowl is pretty much central to either side.. my reasoning for the top being the mouth piece, is that it's been my experience that usually the mouth piece tends to be slightly more tapered and a bit longer than the non mouth piece side, mostly for comfort of fit in the mouth i'd assume..

 

i dont think it overly matters lol but the end with the decoration usually is the end farthest from your face from what pieces iv seen

 

OR you can smoke it with two people at once !!!!!!!