Because they have seen her nakedness— That is to say, her disgrace. For, according to the idea of those times, nothing could be inflicted more ignominious or disgraceful than to strip them of their garments. There are others who give the passage a different turn.
Related Commentaries of Lamentations 1:8
Lamentations 1:8
8 Jerusalem hath grievously sinned; therefore she is removed: all that honoured her despise her, because they have seen her nakedness: yea, she sigheth, and turneth backward.