In my tireless efforts to inform and entertain you, I find myself wrangling a lot of pictures for posts here on CoM. And now that many people are coming at us from Retina-screened devices, we try to use big pictures whenever we can. But how big is a picture?
Clicking the image and tapping the spacebar will give you a preview, but it won’t give you the image’s pixel dimensions. Not unless you install QuickLook plugin qlImageSize.