PNI home: clarify creepiness

[kristinashu]

Based on updates in #3904 and user testing results in #4013. Let's decide if we should go ahead and emphasize the creep-o-meter or add sections.

[kristinashu]

@beccaklam to explore designs more but this is lower priority.

[beccaklam]

Sections from previous exploration:

And extremely scrappy animation of how the sections would work

[beccaklam]

I'm thinking we could combine sections with some added animations to the face. So every time the face changes we could:
a) Instead of having the text changed immediately, have it type in and out like this
b) Have the face "flash", perhaps by an enlargement/spring animation like this

• Alternative spring animation
• Alternative spring animation 2

[kristinashu]

Will look at this as part of - PNI: homepage sketches #5153