I think you need to make a distinction between a broad build, muscular, and being fat. Some dorfs seem to become very obese over time, probably because their professions just keep them sitting in a workshop all day, and you can hang more fat on a wide frame than on a narrow one...
Dwarven clothing is odd from a normal human perspective, in the case of Meng she's wearing a dress that you've more or less converted into a shirt (a dress tucked into pants would probably result in some rather uncomfortable lumps where the stuff that would go down somewhere along the legs would be gathered, making sitting unpleasant). I've envisioned the combination of dress and pants to have the pants under the dress. You're the one with the license, however.
And I guess you have some additional flavor material just in that little snippet: Cracking knuckles (would probably have to be explained: I'm bored...), or "A: Nice engraving!, Meng: Bah, boring"), fertile imagination: "I bet we'll find...", etc. The latter could even be mixed in with some lore when appropriate, as in "Ooh, kimberlite: diamonds, here I come!".
"Feels dejected from being caught out in the rain" vs "Complains only mildly about inclement weather" could probably also be used if that happens to match any of the dorfs.
I agree the drinking is funny, but not really representative... the artist will have to judge where the limits of the license are.