iframe not working

The iFrame option is no longer showing the book that I linked to, but rather a generic “stop hunger” image.
See:http://www.phoenixcentre.com/blog/2015/07/20/elegant-intimate-relating/
It was working fine a week ago, and the text ad (same page, near top) works fine.
Any ideas?

https://ww.wp.xz.cn/plugins/amazon-link/