Josh, you have made few mistakes in the code — for example you have missed the ‘ ‘ in the URL’s of your images. Also your image links have to end with JPEG — you need to use direct image links. At the moment you are using lightbox links which will not work.
How to get a link to your images — just click on an image that you would like to use in your shopping cart →click the SHARE button →PHOTO tab →choose ORIGINAL size →copy the URL from the bottom field — please see my screenshot:
Please do let me know if this worked for you.