At about 8.6 square meters, the mural is four times bigger than zoning rules permit for advertising signs.

这幅壁画的面积约为8.6平方米，是分区规定允许的广告牌面积的四倍。

Casper also devised another code: a triangular advertising sign on the shop window meant that it was safe to come in, if it was placed back to front, it meant that it was better to wait.

卡斯珀设计了另一个暗号: 商店橱窗上的一个三角形广告标志意味着进来是安全的，如果把它放在后面，那就意味着最好等着。