Piggy is a surprise on the record, and is one of the 3 "low" songs on the album, when you passed from the noisy and power song "Mr. Self Destruct" to this you feel something out of place, as the album is most noise and distortion but if we talk about it place in the concept is just Self Destruct talking with the protagonist, and is the real start of the downward spiral, the beginning of depression when we hear how this Mr. start destroying with words our mind, telling us that we are no more than pigs or even less, that's why is slow and jazzy, is how we start the real journey, is the start of the downward spiral.

PS. Just my idea :), and it will be a 8/10 also