not a pretty sight字面意义是“看起来不甚雅观，不好看，不雅观”，可以指任何丑陋、脏乱、不雅、有伤风化或者令人失望、不安、厌恶的东西。语气较为委婉，略带批判意味，可以看作是“辣眼睛”较为委婉的说法。

【例句】
John in his underwear is not a pretty sight!
约翰只穿着内衣，很不雅观！

The bathroom is not a pretty sight. The wallpaper's peeling, the tiles are crumbling.
浴室破旧不堪。墙纸剥落了，瓷砖也裂了。