Is your laptop not among those that can do Multi-touch? Don't feel badly, you can replicate those great features!
Well, kind of. First, open an image with Quick Look. Next, hold down the Option key while performing a two-finger scroll. The image zooms in and out!
Finally, let go of the Option key but keep your fingers in place on your trackpad. The cursor turns into a four-point directional, and then you can pan the image within the Quick Look window.
This also works with a mouse and scrollwheel.