Soprry I didn't see the question until earlier. This one is great for the image,which (for me) is a fat and evil face, fat enough to think of as having girth...but the word girth jars a little bit because it is heavily associated with the waist rather than the face. You could play with his ugly mug being slowly wrapped in mirth, or something, if you liked. On the other hand the use of girth may be just the slightly jarring effect you're looking for, because the reader is caught by the unusual insertion. My .02 and the author's own vision is the last court in these things... But the image _is_ vivid...I'm still looking at the picture in my head!