Compatibility with Jetpack Tiled Galleries? width problem…

Hello, I am looking for the best way to install a masonry/pinterest syle gallery.
I tried through Jetpack Tiled Galleries, which gives wonderfull results on other themes. But when I activate it, the gallery width is reduced and seems pushed on the left.
I have red that some themes have similar issues, and the advice given is to contat the theme editor to check for a solution.
Is there something I can do?

URL: http://www.lgphotography.fr/wordpress/flora-2/