This particular example of surrealist advertising was for the Sony company. It's intention was to create a overall impression of what the sony product would give you. Its actual appearance represented a feeling that was happy and joyful. This emotion was trying to resemble what the product would give you but also made you feel. The reason why its surrealist is due to use of coloured balls that doesn't relate to actual product. In addition the connection between the street and this unusual event ,contributes to it being surrealist and therefore visualising something different.
Its unique selling point is the adverts idea and how it has longevity as a advert.