Preview can modify images. There's a button with a pencil icon that toggles a toolbar for simple image editing, such as adding lines, shapes, or texts.
I've been using the Markup in Preview since they went system-wide in macOS Mojave. (Today I learned that Markup debuted as an extension in Mac OS X 10.10 Yosemite. [0])
This comment and its children sent me on a spelunking mission and the treasures I found. Markup has a Loupe tool and Speech Bubbles.!
Such features are many, various, and somewhat obscure, akin to Easter Eggs. (Both undiscoverable and handy to know.)
