This pet peeve of mine is a quickie, and it involves the first thing most* readers will see when they get to your submission: the cover letter. Normally, this lists the author’s publications, maybe a bit about their “pedigree”, and occasionally a bit of plot synopsis. Sometimes it will note if the piece is plucked from a larger work. Personally I think cover letters inevitably sound super pompous, but I have read my own, and after much experimentation I am not sure it is possible to brag about your accomplishments without sounding self-centered. So go ahead and brag a little bit. You are going to sound silly either way, talking about yourself in the third person. One thing it should not mention, is brief explanations of your use of literary devices, and their respective significances. While you may find it helpful to alert the editors to the fact that your character’s actions to his family throughout the piece are meant to indicate his underlying personality–just don’t put that in your cover letter. If you’re really unsure, maybe just put an asterisk in the important sections, explanations in the footnote. *Some magazines remove the name, title, cover letter details before reading manuscripts–they usually note this in the guidelines if that is the case. And at other places–I am sure there are some readers who prefer to avoid the cover letter experience at all.