Why does Mike Portnoy have many faces?

Whenever I see DT's liner notes or see pictures of the band, I just can't help but notice how Mike Portnoy's facial and body features constantly change. I think the most obvious is his face. Did you see how he looked in IAW album. He was like a skinny glam rocker. Then in Awake, he looked like a hippie; a macho biker in ACOS; a happy beer-drinking man in FII; and the short-haired practical man in SDOIT. Then his body from skinny to the pregnant man which I think is perfectly normal.

I don't know what you think but that's what I saw and what I can describe. What are your thoughts?
 
What do you think is better someone like Yngwie or someone like Mike P.?

never changes vs. changes ?