Before the recent changes to the top bar, I'm pretty sure that review queues were always listed in descending order of items pending. Now we have a drop-down preview on the review icon (thanks!), and I can't figure out what determines the order. It's not number of items pending (either ascending or descending). It's not a fixed order of queues. And it's not necessarily the same order as on the review page when you click through to it. Examples follow.
This is not a duplicate of this question about the SO top bar. The SO and network top bars aren't the same, and neither of the explanations on that question, including one from Shog9, is consistent with what I am seeing now. If Shog's explanation is correct then Close and Reopen should be first on Writers (they're not) and not first on Mi Yodeya (they are). I don't have enough reputation on SO to check whether what that question reports is still true there.
This is what I currently see on Writers, where I am a moderator. The sizes of the queues, in order, are: 0, 0, 2, 0, 3, 1.
But it's not a fixed order of queues either. This is what I see on Mi Yodeya, where I am also a moderator.
And it doesn't match the order on the reviews page:
The reviews page is in descending order, as usual. I haven't looked at enough cases with the new topbar to know if that's consistent, but I'll assume it is.
This is from Meta.SE, where I am not a moderator, so it's not somehow connected to moderator status.