Click the Link box if you want a link to the original file.
If the Link box is marked, whenever the document is updated and loaded the bitmap image is reloaded. The editing steps that you have carried out in the local copy of the image in the document are re-applied and the image is displayed.
If the Link box is not marked, you are always working with the copy created when the graphic was first inserted.
To embed graphics that were first inserted as links, go to Edit - Links and click the Break Link button.