On SIX maps this doesn't show up on as being a trig, however on OSM it does show up as such. And further, the road it's called Loftus Trig Trail (but Loftus Ridge Trail on Google Maps and SIX maps).
Personally I think it's more an observation tower (you can see the climbing steps (taken off) and the area to stand in) but they don't match the ones I know from (dutch

Anyway, who wants to give their two cents on it?