From the Chassidic Masters

Perhaps it was the oils of the black bird's feathers that refracted the light of the sun into so many rainbows. Perhaps it was the mystery of her absolute blackness, or the contrast she held against the bright morning sky. All that could be said is that it was a beauty as indefinable as black is dark

What attraction could the idol Pe'or, and the particularly repulsive rituals associated with it, possibly hold for the Israelites who succumbed to its influence?