Aerangis Fastuosa mounted or in pot?

[Ray]

There is "mounted" and there is "mounted".

To most, that means on a piece of wood, virgin cork bark or tree fern, with maybe a small pad of sphagnum to hold moisture. Unless one has very good humidity, it is difficult to keep up with watering in home environments.

What you have there can be thought of as "an inside-out pot" in which the plant is growing in the moss medium. That moss will certainly hold water better than a slab of wood with a small moss pad, but being as it's basically all surface area, should not present any issues with root suffocation.

I like that idea, and may fabricate a few for myself!

Let me add a general comment: "mounted or potted" has very little to do with the plant; it has much more to do with your growing conditions and watering preferences.