Pinning seems okay but image not showing up on Pinterest

Hi,
Thank you very much for that plugin, it seems great.
However, I am experiencing a problem when trying to pin from my website.
Everything seems to work okay but when I then look at the pin created, there is no image attached to the it. Only the description is showing up.
The three images that can be pinned are at the very end of the page.
I am using the “Enabled class” to activate the “pin it” button for those images only.
Hope you can help.
Thank you very much in advance.

The page I need help with: [log in to see the link]