Hamish has watched the film on the Scottish Screen archives previous linked in the Gurn and once again he helps bring past events back to life for us.
Near to the junction of Albert Street and Seabank Road and in the latter there is a large house named 'Linkside' - I believe that in the 1930's it was owned and occupied by the Arburthnot family - and beyond that in the direction of the shore there was a property with the name Kevin. This really is taxing my memory but I'd say that the entrance gates shown in the film clip gave access to that house. If the large white building seen in the background is the Golf View Hotel and the clip of Mr. Lamb and daughter walking the ponies along the Prom confirms that the hotel was a white building at that time then if the building in question is not Kevin I'd say it is one very close to it.
Incidentally the "mystery beast" picture is one of a fairly large badly burnt tree root. It won a gill bottle of whisky as a prize in a competition run by Aberdeen Press and Journal.
Best wishes Hamish