Design illustration is like explaining a design idea with words, making it easy for people to understand without actually seeing the visuals. Let's say you're talking about a cool new website design. You could say, "Imagine the homepage like a clean, modern magazine layout. Big, eye-catching images at the top, smooth navigation buttons, and a sleek color scheme to give it a classy vibe. It's like flipping through a stylish digital magazine, you know?"