Sharam is right. Dont look at any one part, but the heli as a whole unit.

Orientation of the heli, becomes natural as you progress in your training from hovering to forward flight to acro to 3D.

I lose orientation watching others fly sometimes, but rarely when I fly. Its because I know which way it is turning/flipping/rolling/pirouetteing etc when Im in control.

you will find progress difficult if you develop a BAD habit of using the disc, tail boom, skids, or worse - training gear balls, as a reference for the helis orientation. You MUST use them all together, and see the heli as an entire unit.

Not as daunting as it sounds in real life...

I see you're already in forward flight, and in my opinion if the heli is flying toward or away from you do need to look at the disc (as well as the fuselage) to determine if the heli is straight and level. After all, the disc is the helis wings. When the heli is at any distance, i find the tail, pod, and disc the 3 critical (and only) visible cues.