Ev may be right about that. My poem was a longer one. I'm certain that it has nothing to do with the quality of your work. If they didn't like it, they wouldn't have accepted in the first place.
Don't let this be a blow to your self-esteem. This could even be an honest mistake, really. Those folks tend to make lots of mistakes, from rejecting ms twice, to misspelling their own mag title incorrectly! It could happen.
I would just let it go, really. But if it is bugging you, you could always e-mail them and ask for claification.
buglady