I’m sorry I have to let you know that reading this ask nearly knocked me out of my chair. Thank you so much.
To answer the actual scenario, these two might actually have trouble even perceiving each other, and even then that might be with the help of the Lounge. Luckily there’s the no-harm magic around so that giant Jacob speaking wouldn’t shake mini Jacob apart.
Beyond that, their sizes are so different it’d be hard to comprehend. Giant Jacob definitely can’t see the little guy as more than a speck. Meanwhile the little guy’s whole entire sky is a face. What the heck. Why this. He’d have to dive into someone’s satchel to just try to process the size difference. Do not leave him on that giant’s hand; he’d get lost.