In plain words
Swapped letters, an added hyphen or a different ending make an address that looks like yours at a glance. Your own DMARC record does not stop it, because it is a different domain.
Why it matters to a firm
A look-alike set up for email with no website is a common start of a forged invoice. We never say who owns one or what it is for; we show the public record and ask one question: is it yours?
The check behind the finding
Type two or three misspellings of your domain into a domain registration search and see which are taken.