What do we learn from "Hakaras Peneihem Onsah Bam"?
Yevamos 120a: If one saw the forehead but not the face, or vice-versa, he cannot testify who it was. He must see both, including the nose.
Rashi #1, Targum Yonasan: The sin of Hakaras Panim (favoritism) in judgment testified against them in front of Me.
Rashi #2: They are recognized via the brazenness of their faces.
Radak: This is like "v'Es Echav Lo Hikir" (Devarim 33:9). One can recognize in their faces that they are evil like Sedom.
Radak citing his father: The brazenness of their faces [testified against them]. And so he explained "Lo Sevoshu Tahkeru Li" (Iyov 19:3). In Arabic, Haker is brazenness.
Malbim: Signs of hypocrisy and flattery are recognized in their faces. They testify about the falsity in their hearts. One can recognize (distinguish) on the face [between] one who truly fears Hashem, and a hypocrite.
What is the meaning of "[v'Chatasam] ki'Sdom Higidu Lo Chichedu"?
Rashi: They did not deny; they did [evil] openly.
Radak: Also they tell their sins with their mouths; they do not deny. This is like Anshei Sedom, who glorified themselves in their evil.
Malbim: Even if their evil way was hidden regarding matters Bein Adam la'Makom, their sins Bein Adam l'Chavero resembled those of Sedom; they openly sinned.
Why does it say "Oy l'Nafsham Ki Gamlu Lahem Ra"?
Radak: Their Nefesh will perish when they die, due to their evil deeds, aside from the punishment that will come to them in their lifetimes. They bestowed evil to their Nefashos, i.e. to themselves, via the evil that they do to others.
Malbim: Even if they deceived, they deceived only themselves; they bestowed evil to themselves.
