That is actually one of the more believable things about the image. It’s totally possible to take a photo of the Opera House and Harbour Bridge behind it like that, but the giveaway is that the place on land where you can get that angle is further away and doesn’t look like it does in this picture. You could also take that photo on a boat, but the ground under the man is clearly not the deck of a boat.

Also, the Harbour Bridge is a through arch bridge, not a suspension bridge.