If I have my laptop or phone our during a meeting it's because I've either already had this meeting with whoever if giving out the information and don't need to

If I have my laptop or phone our during a meeting it's because I've either already had this meeting with whoever if giving out the information and don't need to pay full attention to it or I'm in a meeting that I shouldnt be in because I have nothing to add. I assume everyone else is the same way and It's a really easy way to tell who does and doesnt need to be in future meetings for me.