(Not GP poster.) I don't really have a problem with masonry layouts, but a newspaper is limited by the paper size and they have incentive to squeeze everything in there (to maximize the spread of "information"). The screen is theoretically infinite (although not for kiosks).

I do have a website with a lot of images, and at the moment everything is in a 3-across grid layout...

Yes, I have. Printed, which is fundamentally, and literally a different media type with different properties