My personal theory on it is that what they really want is a device with an actually clear screen kinda like a Hololens, but not shitty and huge. Unfortunately technological hurdles prevented them from doing that, so this was their solve.
I suspect this eyes-through-the-device form factor is philosophically a branding element to them so they're faking it until it can be real to maintain some consistency.
I could be totally wrong though and it's more simply trying to "humanize" the things or some such. They're an idiosyncratic company sometimes. I would also not be surprised if they release a cheaper model in the future without it.