Unfortunately, rather than share the first screenshot, or small promo image, it seems to share only the icon – which looks awful as it's blown up to the size of a full social image, and set to cover not fit.
On Twitter, again the icon is shared, but it's placed to the left, and though doesn't look terrible, is not the full, glorious screenshot.
On Facebook, and the Facebook sharing debugger, nothing shows:
On my own site, I have it set up to show a specific opengraph image (which looks great):
Looking at the OG tags in the Chrome Web Store page, it seems they are there, but they do in fact show the icon:
The opengraph image is probably the most important thing to get right with opengraph sharing.
Unless I've got something wrong (I checked a few other extensions too, and they all show the icon) can I request that we get better support for this?