First of all, this sentence shows Yu Ji's deep feelings for Xiang Yu. In traditional Chinese opera, Yu Ji loved Xiang Yu deeply, but Xiang Yu had to leave her because of war and political reasons. Yu Ji saw Xiang Yu sleeping in his tent, and her heart was full of sadness and thoughts, which showed her deep affection for Xiang Yu.
Secondly, this sentence also expresses Yu Ji's sadness. Yu Ji knew that her separation from Xiang Yu was inevitable, and she also knew that Xiang Yu's situation was very dangerous. So her heart is full of sadness and helplessness, and this sentence also conveys her feelings.
Finally, this sentence also reflects Yu Ji's concern and worry about Xiang Yu. Although Xiang Yu was the overlord of the West Chu, he also faced many dangers and challenges in the war. When Yu Ji saw him sleeping, her heart was full of concern and worry about him, and this sentence also showed her feelings.
In a word, the phrase "Farewell my concubine, look at your bedroom clothes" in Farewell My Concubine expresses Yu Ji's deep affection, sadness and concern for Xiang Yu, which is a very important lyric in China's opera.