My t does glance at the clock now and then, - it is on the coffee table so we can both clearly see it. She never yawns, and no googling, or any devices, - though she did let me lean on her ipad to write some stuff down once. I think she regretted it when I got all shaky, and said to put it down carefully
I would be peed off if she yawned. She does sigh a lot, but sort of with me, rather than at me.