The actual scene of Edmund putting the glasses and mustache on the stone lion in the book is really funny, and I was kind of disappointed that they didn't include all of it in the movie.
What happens is that Edmund walks up to the witches castle, still sulking from being yelled at and ignored by his siblings, when he comes into the courtyard he sees the stone lion and hides from it, thinking that its a live lion. After a few minutes he notices that the lion has not moved, so he cautiously peeks out from behind his hiding place and walks over to the lion where he laughs and says "Stupid lion, I bet this is the great Aslan. It looks like the Queen's already turned him to stone. Boy, won't the others be disappointed!" After that he picks up the burnt stick and draws glasses and a mustache on the lion.
I was really happy to see the lion with glasses during the coronation ceremony. I laughed really hard at that part!