It also took me back to the slideshows of my childhood. My dad would deploy one of those tripod-mounted projection screens and, if I was lucky, I'd get to use the handheld "clicker" to advance the projector's carousel. Because they were near-weekly events, we saw the same photos over and over again, and we'd often spot details that were overlooked the first 17 times around: A picnic shot revealing a surreptitious cookie grab, a near-perfect family portrait in which yours truly was flying low.
These days, new observations are even easier to make as we rename, sort, crop and share images. Indeed, upon further review of our time in the Land of the Long White Cloud...