This is another masonry gallery that works in columns. The number of columns adjusts to the width of screen/parent, but it have it in a medium-12 columns to show what it looks like by default, it increases columns at larger widths. It uses the same lightbox as the horizonal masonry and easy square. To add and remove images, you just need the image tag, with its src and 'rel="lightbox[gallery]"' you can have more than one gallery by changing the "gallery" to any other id you want to give it.

(This does not stretch to fit the full height, I could not find a solution but if you do, let me know.)

UPDATE: you can have a different thumbnail image, or a compressed version of the image by using the srcset attribute in the image tag (ex. <img src="/wahelper/GetImage?id=275749" srcset="/wahelper/GetImage?id=275749&width=400" rel="lightbox[gallery]" title="Caption" /> )