VideoAsk (by Typeform) is excellent at one thing: asynchronous video conversations and forms, surveys, applications, lead capture, often on its own hosted page or a pop-out.
Where they differ
Nook is designed to live on your site as ambient, tap-to-play answers. Visitors don't fill out a video form, they tap a page-aware question and watch a short reply in the exact moment they're hesitating.
Side by side
Interaction: VideoAsk leans on visitors recording or typing a response; Nook is tap-only, nothing to type. Placement: VideoAsk shines as a standalone funnel; Nook is an always-on widget on every page. Questions: Nook suggests questions based on the page; VideoAsk follows a flow you build.
Which to choose
Use VideoAsk when you want a video form or async back-and-forth. Choose Nook when you want a real person quietly answering the questions that stop visitors from converting, without making them do any work.
Comparisons reflect each product's primary use case at the time of writing; check their sites for the latest.