The link images option is very useful if you are still working with your image in your favorite editor (Adobe Photoshop, Adobe Fireworks...) and you want to build your prototype at the same time.
It will give you the freedom of having images in your prototype but they can reload themselves when you make changes in your editor.
You can choose to link images when you start a new prototype with images or afterwards, when you set an image in your prototype.
Starting a new prototype with images
In the dialog, you can add as many images as you want. then, you can select to link them in your prototype. This option will be applied to all your images.
Setting a linked image
When you set your image in your prototype, a new dialog will appear to ask you how do you want to set the image.
For every image you set in your prototype, the dialog will appear and ask you about what to do. However, the dialog will remember your last selected option.
When you have an image in your prototype, you can do multiple actions over it. If you show the context menu from an image component, you can find some image-only commands. Those commands are also on the image toolbar and the image menu bar. Here is a screenshot of the context menu of an image:
Note: by using the crop or flip commands, the image will lose the "link" status and will be embedded with no warning.
If you have a linked image from an external device and you lose the connection or if you delete the image file from your file system, Prototyper is not able to continue refreshing your image. In those cases, you won't lose the image nor the link status. The image is stored inside the working folders of your prototype, so if anything happens, there is a copy of your last change you made. You will only notice the broken link by looking into the top-left corner of your image and look for a warning symbol.
Once the connection is restored or the image has been put again in its original folder, the icon will disappear, and the images will be keeping updated again when you modify them.