Interested in Language
When enlarged, you can also move around the picture by dragging. Click on any portion of the picture, and with the mouse down, move it. This will move the picture, and allow you to go through any part of the book in detail.
Could you tell me what "with the mouse down" means? I have no idea. The above sentences describe how to use a computer to view pictures.
It means while your finger is still holding the mouse button down (unreleased).