Oh, now I understand. If you'll look at the screenshots page on the Inkscape website, you'll see what they are a looking for. It's not just screenshots of the dialogs of new features. It's screenshots showing how you're using a new feature, in a drawing. Like maybe you're doing a drawing where you need specific measurements, so you can use the Measurement tool, and make a screenshot of the whole Inkscape window, in the middle of using it. It needs to be something fairly eye-catching, since the placement of that Screenshots page is meant as sort of an advertisement for Inkscape. So maybe a drawing of a map, or I don't know. I haven't actually used the Measurement tool yet.
It turns out not to be something that people are jumping on though. So there's no rush apparently. Although there is one new one for 0.91
https://inkscape.org/en/about/screenshots/. And rats, that's exactly the one that I wanted to make a screenshot for!
