I've received an email with a link to a dropbox with photos. When I open the link, the photos are listed by their names and extension .jpg. I don't know what to do next. The page has "Extract all," "Comment," "a comment box, " "a down arrow" and a "copy link." All I want to do is to save them to a thumb drive connected on the Macbook pro computer. How do I do this, please?