Australia: Which wire is hot / active and which is neutral?
In Australia and New Zealand, the general rule is that 


any wire with green on it has to be earth, 
any wire with blue or black on it has to be neutral, 
any wire that does NOT have blue, black or green on it has to be phase (hot).  


So in this case, the pale grey wire from the ceiling is the phase wire, and it's correct to connect it to the brown wire in the lamp, as shown in your photo.

Also, if the lamp doesn't have any metal parts within normal reach, then it typically won't have an earth connection.  In that case, there's nothing to connect the green/yellow wire from the ceiling to, and it's perfectly correct to leave it unconnected.  

I believe the wiring in your photo is correct, and up to code for Australia.  It's not a sloppy job at all - it looks quite professional to me.

Having said that, I am neither a lawyer, nor an electrician,  nor an Australian; so please do not consider this to be normative advice about the Australian electrical code.