Adobe Portfolio: Stagger photos on page

I am using the matthias theme in adobe portfolio and was wondering if there's a way to get rid of the blank space between photos. For example if I have a portrait photo next to a landscape photo theres a lot of extra space where the landscape photo is and i'd love to fit photos underneath it but I don't know how. I would like to limit 2 photos per row and have them each aligned 50% so its equal and formal. Im gaining inspiration from photographer Joe Greer's website, so I attached a photo from his website of what I am trying to do. I hope this made sense, thanks!