When you wear a holographic computer on your face, you gain some things and lose others. That's certainly the case when using Skype in Microsoft's HoloLens. Some video chats will work better because your caller can see what you see, rather than your face—but others just feel weird.
As you'll see in the above video, I recorded a call to myself from Skype on my laptop to Skype on the HoloLens. For the most part, it worked rather well and about the same as it would between regular computers and smartphones.
You don't miss seeing another person's face when you're just video conferencing with yourself, but you might if you're actually talking to another person. You can hear them, and see what they see, but that's something most of us have experienced by toggling between front- and back-facing cameras on our phones. Imagine you could never toggle back to the front-facing camera and you'll understand the dilemma with using HoloLens.
Microsoft may use holographic representations as a stand-in for your face in the future. We've already seen how a Kinect can make that happen, but you can't really hook one up to the HoloLens (nor would it be practical to do so).
Instead, the headset's motion tracking and speech recognition could inform the movements of a rendered hologram of your choosing and send that to the other caller. They'd still see what you see, but a holographic representation of you as well so it at least feels like they have someone to talk to directly.
But that's just conjecture. Microsoft already wants you to look at video conferencing from a different angle, as their video above demonstrates. They believe that sharing your line of sight with another is just another method of communicating, and a more practical one.
Instead of just calling someone up for a chat, you'd wear the HoloLens and use Skype to have a friend assist you in a task. When you're remote and need help with something, you don't want to send video of your face but rather video of what you're doing.
Skype on the HoloLens supports this method of video conferencing quite well. It gives you a pen and arrow tool for marking up your space and pointing at specific objects. The arrow tool is as simple as air tapping where you want to mark an object, but it's rather difficult to be precise with the pen tool due to the HoloLens' limited field of view and serviceable yet imperfect hand-tracking abilities.
Using Skype in the HoloLens should prove useful in several practical applications. In fact, it feels like a useful upgrade when you use it the way Microsoft encourages you to. However, if you're just having a conversation with another person this format feels a bit weird. The pen and arrow gimmicks make it fun, but eventually Microsoft will have to find a better solution for standard conversations. Or, if not, we'll just have to start standing in front of a mirror.