What is the significance of taking her garments, and what does she cover with them?
Radak (according to the metaphor): The harlot covers the Zonim with her garments, to beautify them in her eyes, and to draw their hearts to her.
Radak (according to the Mashal): She covers the idols.
Malbim: After making Bamos from her garments, she is left only with Bigdei Rikmasah ? "va'Albishech Rikmah" (10), i.e. the Kesones, which covers her flesh, and covered the idols with it.
Why does it say "Shamni u'Ktarti"?
Radak: This is like it said "Asher Nasati Lach" (17).
Malbim: It is of Hashem.
It is written Nasati, and we pronounce it Nasata!
Radak: The Kesiv teaches, it is as if I put it in front of them. I caused it via giving it to you. Chazal gave a Mashal (Brachos 32a; one said to his animal) 'who caused you to kick me ? the vetch that I fed to you!'
Malbim (19): [It is as if] I put it in front of them. Refer to 16:19:3:2.