GNOME Sushi adds a macOS style ‘Quick Look’ feature to Nautilus. Just select a file and tap the spacebar to see a larger preview.
There are many sites that list useful QuickLook plugins for OS X users but many of them have missed this one. Now, when you’re in Finder, a simple tap of the spacebar can show you the dimensions of an image and its file size in the title bar:
But wait, there’s more!
This plugin can also preview and generate Finder thumbnails for unsupported images formats like :
AND it comes with a Spotlight plugin to display informations of unsupported images (WebP, bpg, Portable Pixmap) in Finder’s inspector window. But really, it had me at displaying the dimensions and size of an image, since that’s information I’ve often needed after receiving an image. Real all about it at the project’s GitHub page or just download the installer.