How does one occasionally cut away to an observer without completely messing up the flow of the foreground scene?

For context, there is a group of characters being watched over the course of several scenes. The primary action involves those characters, but I want to indicate that the observer is doodling a sketch of them. Each scene might have one or two glimpses at this sketch without revealing more than the observer's hand.

Using INTERCUT or formally switching scenes back and forth seems like overkill.

Hey FrankM.

I recently used a "BACK TO" for something. Not sure if that would help.

https://johnaugust.com/2015/short-cut-aways-and-the-value-of-back-to

Hmm. Perhaps italics maybe?

BACK TO: will definitely be helpful. I'm just a bit squeamish on how to get to the sketch. This starts happening in the middle of character intros for the main group, so I don't want to get the reader lost or put them into the mindset that the whole film will be frenetic.

Italics might do the trick, except that I'm already using italics for titles that appear in action lines. I'm afraid if I mis-punctuate a book title in quotes, some librarian will come after me with a butcher knife

Yeah. You don't want it to be too distracting.

Hmm. How about CAPS?

IN THE BACKGROUND. AN OBSERVER doodles A SKETCH of the group.
THE SKETCH is half drawn.
BACK TO THE SKETCH.
THE SKETCH is filled in. THE OBSERVER'S HAND is revealed to be...

Just an idea. Hopefully more natural than lots of cuts.

You can use each character's name as a sub-heading.

A quick example:

INT. PARTY - NIGHT

Jack dances a tango.

GEORGE

spins around.

JENNY

sashays her hips.

Or you can simply write each action as normal. No need for an actual quick cutaway as this should be implied by the context.