UX Basics: Spacebar to open image(s) in Preview

In Freeform and many other Mac apps, when you press the spacebar it opens the selected object in Preview. If you have several images selected, then Preview will show left/right arrows at the top left allowing you to cycle through all the images you are Previewing. If you have several similar images in a moodboard and you want to quickly flip between them because you have to choose one for a project, this helps you compare them.