Word reference?

Hello everybody.

I'm reading The Emotion of Design by Greg Hoffman.

can’t really tell
you how Platon does it; how he’s able to tell a story through his portraits
and elicit a response from his audience that exposes some truth about the
human experience. But I can tell you how we, as brand marketers, can
strive to achieve it.

Would you please tell me what it in the last line refers to?

And about the human experience, does it refer to as something general or the human experience of that certain portrait?

Thanks ??