We learn new stuff everyday. A tiny fraction of the bits that we don't filter out, sometimes stick. But we filter out a lot, most stuff in fact. So it's a challenge for anyone with something worthwhile to say, to actually get through to us.
The solution however is to use our visual curiosity. We are drawn to images that we find intriguing. What gets through consistently are images that engross us and clever, competent illustrations really have the edge here. We literally can't resist them. We simply love skill and imagination. So if you tag something worthwhile onto a meaningful and intriguing image, we're sure to take note.
That then is the essence of visual communication. It's useful when you need to connect. It's vital when words are just not enough.
Visual communication is the purposeful projection of meaning beyond words and illustration and graphics are how it is done.