When you want a jpeg image of your flyer, click on the PRINT button where you will see a button labeled "Create JPEG Image". If you click the button, you will see a progress bar and then a new window will open up. The new window will then take approximately 20 seconds to finish the process of create 2 jpeg images of different sizes.
After the images appear, you can save a copy to your hard drive by "right-clicking" on the image and select the "Save Image As" option.
In FireFox the pop up window looks like: