I only had a quick look at this but it might be the wrong approach. It looks like every time a new photo is concat onto the data array, every single node will b

I only had a quick look at this but it might be the wrong approach. It looks like every time a new photo is concat onto the data array, every single node will be re-rendered, not just the new ones. This won't happen with the raw DOM one because of the "if (!imageInDOM)" line. A better way to do this could be with child components with their own unique key, but since we can't see the render method I'm not sure exactly what's going on. nb: I'm not saying React is definitely "fast" here, just pointing out a potential flaw. I'm also not saying I'm definitely right ;)