Vintage view across the harbour in Polperro towards the Warren. I'm guessing this photo was taken in the 1900s for several reasons. Firstly the quality and sepia make it quite old. Secondly the house in the top right looks post-Victorian but some of the 1920s/30s houses on the hillside are absent. However, there is one big clue that this photo is pretty old - if you look at the hillside in the background it appears to be virtually tree-less. Compared to a recent photo (http://www.cornwalls.co.uk/photos/polperro-harbour-tide-1565.htm) you can see is pretty much covered in trees.
Another difference to today's Polperro is the lack of trademark whitewash. Yes, a good few cottages and buildings appear to be whitewashed, but it isn't the blanket of white we associate with Polperro these days, there is still plenty of bare granite on show.