Since the dawn of tabbed browsing, middle click opens links on a new tab, usually a background tab so you can click a few of them quickly without going back and forth.
If you middle-click a link preview, the little image near the link someone posted, it opens in a background tab like it should, but it also starts the pan mode that usually happens if you middle-click the page background.
This is annoying because its against the standard way that links work and the way we’re used to clicking on links.
Bottom line: if you’re linking to some webpage, showing a preview and making the mouse turn into a hand over the preview, please make it behave like a normal link.
But the link above it, the title of the page is a normal link so it works perfectly.)