Backgrounds are explicitly chosen by CC license. The rest of the photos are already publicly shared and I link back to the original source.

I'm glad you pointed out the width of the image stream not being responsive. This is intentional. A gripe of mine regarding the latest image display paradigms is the over-use of browser width. In my research, the strain on the eyes as a result of two dimensional scanning (up/down + left/right) became annoying very fast. The sweet spot seems to be 3 columns, allowing the eyes to gracefully pan down the page and every now and then look away at the background to prevent excess strain.