Somewhat dissapointed to find that the devices are not actually HTML/CSS mockups, but just a background image of each device sourrounding the screenshot.
Not sure why you would want to compromise on browser support just to have some fancy CSS3 in there. Background image is totally acceptable (in fact, I think that was a great design decision). This library does exactly what the author claims it does.
They could at least be vector. And, could we have flat, solid-color silhouettes of each model?