I have this image hosted through Dropbox and it loads slowly. I need to determine if the location of the server is too far away from my main audience so I can determine if that is the cause of the performance issue.
You can get IP that serves image with ping command or in Developer Tools of your browser
And check it's possible destination in geoiptool but the best solution to check you page speed is to test it with pingdom or gtmetrix, cause distance is not always important. Anyway Dropbox is definitely not for storing images.