It is definately a good way to see how he does it, but it is however a long and painful of doing it in my opinion. Because I do i quite differently, and there a pros and cons to the way I do it.

I basically print screen, open a new document, crop the image to make the individual image i.e. logo. And then optimise it for filesize and save it.

I do this for each and every individual image. A con would be that it can take a little while getting use to for doing it fast. However a pro would be that you get the image(s) more accurate and pixel perfect.