Displaying over the whole page

Hello,

For some reason the gallery doesn’t enlarge the frame that is meant to display the content of the page.

I would like the pictures to appear in a full screen masonry style of gallery, but here they just appear one by one within that narrow frame.

Example : http://jeremie-sallustio.com/prague

Any idea how I could force it?

Best regards,

Jérémie

https://wordpress.org/plugins/flickr-justified-gallery/