WordPress displaying PageBuilder badly

so here’s a weird one…
I have developed a site in WordPress and only have access to a Windows PC…
A Mac user tells me that the eight images in a grid are being displayed in a single column down the left of the screen rather than in a nice 4 by 2 grid…

Any ideas as to how I can stop this happening to people viewing on a Mac…
Many thanks in advance
Dave

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