I can see no way that a DMOZ description can help or hurt a ranking.

In the case here, the site is listed in this category:
Arts: Comics: Retailers
http://www.dmoz.org/Arts/Comics/Retailers/
(ie the catgeory title already has the words "comic" and "retailers"
The site title is:
Comic Emporium
(ie Comic in the title)
The sites description is:
Online comic book store selling back issue comic books from the 1940's through the present.
(ie 'Comic book' and 'comic books' is repeated in the description - thats keyword stuffing of the description and is against the guidleines, even though it was added by an editor).

IMHO, the description should say something like - "Online store selling back issues from the 1940's through the present" as 'comic' is already in site and category title.

BTW - there are a number of other descriptions in teh category that need cleaning up as well (I can't edit there, so can not do it)

CBP