Since it was first revealed in Redmond at the start of last year, I've used HoloLens a couple more times. I did a development session that walked through developing a simple app for the headset using Unity, and I've also seen Microsoft's touring HoloLens experience that it was offering developers last year. Each time I've been subject to tight controls; all usage of the device was strictly supervised, and I wasn't permitted to take pictures or video of the device, nor even take screenshots of the images it produces.
With the HoloLens Developer Edition starting to make its way into developers' hands, Microsoft has at least eased up on the restrictions, and earlier this week I was able to use the device for a couple of hours on my own; not in a tightly scripted, controlled environment, but without any supervision at all. And for the first time, we were allowed to take pictures and photographs when we did.