I get that. I really do. But there's so many things on that list these days. Its what I feel if i'm told to close a laptop when its quite clear i've already made a decision on whether what is being said is relevant to me or whether i have better things to do. I'm also aware of the social power/authority plays involved in such, as well as traditional etiquette.
But i'm also getting to that stage of life where I'm no longer as concerned about whether some numpty feels i'm disrespecting them by prioritising my time against their preferences or being "rude" by being practical.
I'm aware you can't do this in many workplaces/contexts where you basically have to be submissive/concordant with a workplace culture that says otherwise.
But my life is too short for me to worry seriously about such things anymore. I don't go out of my way to offend, nor do i take said actions as some kind of social/political power play. If a person doesnt want to work with me because of that or gets offended, well, rack another one up on the board...
Its not black and white, granted...but I think its more statistically valid that people who make a big fuss about such are more likely to be on my own "waste of time/oxygen" list...
Or, if that is not acceptable due to workplace hierarchy, talk to your manager and explain the problem. If being present is a political necessity, chances are so is not secluding yourself behind a screen.
And may be you missed the point that, like being physically present, opening laptops in the meeting also has significant signalling effects.
I'm not yet powerful enough to get out of the fraud/shit-show entirely :P
If your meeting is not relevant to me, I'll try to get out my laptop and get some actual work done while my time is being wasted or if we meander into areas that are not of relevance.
If you ban laptops, and for some bizarre reason I still have to attend and your meeting is not interesting to me, i'll code on bloody pen and paper and enter some of that code into the computer once I get back to my desk, or i'll try to do SOMETHING productive. Trust me, you don't magically have my cognitive attention...
I had a consultant/workmate try to ban laptops in her meetings. No prizes for guessing whether I think it was the laptops or the meetings (or the consultant) that were the far bigger waste of time/attention/money...
Hire competent people and let them decide what the best use of their time is...or at least admit that you think its justified treating other's in the workplace like children...