One of two things may have happened.
The first is that the owners of the house down the street may have installed the skylight without permission from the Art Jury, which would place them in a condition of non-compliance. There are instances where people are unaware of, ignore or defy the restrictions. Since the Association does not have any field investigators some of these conditions remain undetected. In most cases the situation is resolved at the time of sale when properties are usually required to be brought into compliance by the buyers.
The second thing that may have happened is that the Art Jury approved the skylight down the street and later felt that it made an aesthetic mistake and decided to reject all future submissions. The Art Jury does not feel obligated to repeat its mistakes. In instances such as this, the Art Jury may offer an alternative which they feel is more appropriate given past experience.