Uploaded Images to FTP Not Appearing in Theme

Hi,

I had a theme installed on one of my websites and wanted to use it on a new one I am making, so I copied the folder (using my FTP) and uploaded into the themes directory of my new site. When I did this the general look (colours etc.) was there but none of the images were showing – such as the header image of the background image.

This is a link to the site: https://www.theacklesonline.org/wp/

This is basically my first time using WordPress so I am really stuck here :/

I uploaded everything in the folder just like a normal theme and cannot understand why this is happening. Any ideas?