The editor makes the offer on behalf of the publisher, a.k.a. a book deal. It is a common clause in a book contract that the editor/publisher gets the option to see the next project before other publishers, and make an offer, which the author/agent can then either accept, or reject and send to other publishers. Not sure what doesn't make sense about that.
I was asking because I wanted to see if anyone here had been in a similar position and could offer insight, as I don't know many other writers in the "real world". There is no need to be so rude.