We set up some data collection a few weeks back to look at the distribution of actual screen size, viewport size and media viewer canvas size on sampled users. This will ultimately be used to come up with a better choice of thumbnail size buckets for Media Viewer.
I had some spare time and figured I'd try to generate a visualization of that data, which we haven't analyzed yet.
I think it shows quite strikingly how screen size really doesn't matter much compared to the actual available viewport. Hopefully this data will be useful for other folks too, since I don't believe we tracked that information before. And given media viewer's traffic, it should be pretty representative of wikis in general.
The data used to generate those images is all the data we've collected so far. I haven't looked at differences between wikis, etc. For people with analytics access, the EL table I dug that data from is MultimediaViewerDimensions_10014238
Note that this is mostly desktop, since it's very unusual to run Media Viewer on mobile devices, considering it hasn't been made for it and themobile site has its own MV-like lightbox.
