The old Armoury wasn't interactive at all. You would get into a magic range and could then buy stuff which would immediately be added to your inventory and display at your body. I think for both gameplay reasons and implementational effort we will keep it like this. This means that the player will never really interact with the Armoury. However, it is possible to fake an interaction by
playing one generic animation and/or sound whenever a player buys anything.
showing a particle effect at the player and/or the Armoury, illustrating the beaming process.
drawing some energy beam between Armoury and buyer.
Note that in all these cases it isn't relevant what the player buys and it will even work when multiple players use it at the same time. In the 3D printer example, a player would get in reach and use the buy menu or a keybinding to quickly buy three items. The Armoury would then play the generic printing animation once (it starts when the first item is bought and will ignore the other two buy actions since there's already an animation running) and there might also be some beaming effect such as a small ball of light being fired at the player at the end of the (short) animation or something like that.
If you add a screen to the Armoury be aware that it will most likely be eye candy with no interactivity. However, in case we get ingame-UI support in the future (think of Doom 3, where you had these screens everywhere and your crosshair turned into a mice whenever you were close to one) we can probably put such a UI on the screen and it would serve as a third option for buying stuff, potentially displaying the same buy menu that would usually just open in the middle of the player's screen. But that's not really in reach for now.
So, to answer your question in short, the Armoury should beam stuff onto the player but it may have moving parts that will play a generic animation whenever it does so. I also like the idea of having it resemble some sort of futuristic industrial 3D printer/teleporter where stuff isn't stored but created on the fly.