Hi everybody,
That svg example file has not width and height attributes defined. This is the problem. I don't know if Snap! must solve this and use the attribute viewBox (defined in that example as "0 0 45 45" to its visualization as other viewers do).
But here, you only have to edit that file and add width="45" height="45" to the svg tag, and "this cheese" will appear on stage!
Checking "width/height of costume" reporter you will see this problem.
Joan