Here's how I see it. We are supposed to see that Diana is not in her own words "doing this very well". She wants Tom to understand what she meant by the whole "I don't love you" thing and the idea she was just using him as breeding stock (as she says the two of them alone could not have repopulated Themyscira alone and if she just wanted someone to breed with she knows a lot of smart, single hunky guys within the super-hero community). I think she's showing him (badly) exactly how much her feelings have grown from mere attraction even if she still doesn't "love" him (something she still never says). Diana's the one who screwed this up and here she's just not making it any better - which I think was Gail's point.
Tom/Diana are finished (for now I guess, Gail has said he's gone from the book, but some other writer will probably bring him back at some point) because of miscommunication even though they care for each other while the Alkyone/Achilles sexless political marriage is going ahead (later in the issue) because each side knows the score. It's a study in contrasts.
Two other things that came out of #36 for me: 1. Gail has said (in other places) that this was how it was going to play out from the get-go. Knowing that in hindsight and knowing that neither Heinberg, Picoult or any filler writer did anything more than make the long time super spy seem more like a "frat boy", I've been impressed in how the Tom/Diana relationship progressed. To be honest, I've never liked Tom more (as a WW character, I've always liked the Suicide Squad version of Nemesis) than in the last half dozen or so issues or believed until then that Tom could indeed be a suitable replacement for pre-Crisis Steve Trevor (which I think Heinberg clearly was aiming for). In fact, I was never MORE in favor of the Tom/Diana coupling than when it was over and I think that's a sign of good writing considering that when Gail took over the book Tom had very little personality to begin with.
2. Lopresti's art probably impressed me more in this issue than any other. In scenes like this precise facial expressions are very important (and more difficult for many artists than action scenes) and I think AL really nailed it. The chagrined Diana in the second to last panel basically says everything you need to know about the entire sequence.