Standing before alpacas the first thing you notice is their eyes. There is more behind the eyes than a lot of animals and you find they are watching you watching them.
The second thing for me is the nose - watching the nostrils almost like they are leaning forward without moving, trying to gather more intelligence on you.
The overriding impression you get from alpacas is curiosity.
If you can go spend some time with an alpaca and see what you can see.