I can’t add PinIt button in portfolio

I can add the PinIt button to the blog and pages… but I don’t know why I can’t add the PinIt button to the images of the portfolio.

I thank that the problem was with the link to Lightbox that there’s set in the photos, but I delete it and the PinIt is still missing.

The images on the portfolio had this structure:
<div class=”mkd-portfolio-single-media”>



</div>

Do you know how can I solve it? Thanks!

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