If you choose Save and Open, the same dialog window will appear, prompting you to save the file to a location of your choice, and then open it in your default .jpeg, .gif, etc reader, such as Preview.
If you select Change Patient, you may change the patient associated with the attachment, provided that the attachment is not associated with an Order. If the attachment is associated with an Order, the following warning will appear:
If this occurs, you will have to remove the attachment from the Order in Patients > Orders by clicking on the red minus button:
After an attachment is disconnected from an Order, you will be able to successfully change the patient associated with the attachment.