In that first technique you hold your attention on a thing as perfectly as you can for a time.
That thing can be a visualization or it can be any of a hundred other things.
My favorite is the feeling of breath in the tip of my nose. It’s a popular one. No visualization required there.
Engineers are, as a rule… well, you’ve seen what they’re like. You gotta loosen them up with drugs first if you want a decent conversation.