Does anyone know if the Mavic 2 Pro autofocuses on the point of interest (POI) when in a POI intelligent flight mode?

I was circling a shipwreck yesterday using POI and moving closer and further away. The ship looks as though it's always in sharp focus, despite the fact I didn't tap to focus.

Was this a fluke or feature?

As the point of Interest was likely at Infinity, it would stay in focus at almost all except very close distances.