Help with Product Landing Page - images disappeared

I’m not sure what exactly happened, all but one of my images disappeared or the link broke.
I edited most of these images to have a transparent background and then saved them to my online dropbox. I then used a dropbox link in the coding. Everything worked great…until it didn’t. Not sure why.
I appreciate any feedback on this problem.
Thanks!
Here’s the link to my codepen:

It looks like codepen is blocking off sources from dropbox (Not 100% sure though).

If you open up console in your browser you will see bunch of errors about Content Security Policy violations. I would google this error and find alternatives on how to bring images to codepen.

The images are back. Not sure what was happening with codepen, but things seemed to have fixed themselves. Thanks.
K-

They disappeared again, but I read somewhere that if you upload images via your desktop dropbox instead of going to the webpage dropbox, the images will stay linked.
Another option I read about was using Postimage.org. I haven’t tried that option yet, but will in the near future.