Hidden streets of Edinburgh

I've walked down this back street many times on my way from Broughton St. through to Union St and the top of Leith Walk. I've just discovered that it's called Broughton St. Lane. I really enjoy walking down this lane and many of the other small streets in Edinburgh because there are so many varied architectural surprises. I've been wondering what the little doors in the peak of each low building on the left are/were used for. It seems like something that was used for delivery and storage of something?? I also love the little balcony full of flower pots in the building directly ahead and the colourful bins (makes them a little bit more interesting anyway!) 
Well my errands are done for the day, I've purchased some great food from the health food shop and I'm determined to get on a more healthy track for the New Year. Now I'm off to the gym..loving my days off!