Speaking Versus Acting

I've been following several discussions about speaking on LinkedIn. One controversial question is: Should speakers act? Are acting and speaking different?
Being Yourself Close-up
I think people join Toastmasters International because just being yourself is not enough. Watch any vox pop interview of the public and they um and er, change their minds, swear, don't know, think that 'you know' instead of telling you, and bore everybody by not getting to the point.
When you talk close-up to your Mum (Mom to you in the USA), she knows you and you can be yourself.
Acting On Stage To Be Seen And Heard
However, as soon as you get on stage you have to be seen and heard by the stranger in the back row.
A slight grimace or wince can be seen by those in the front row, but the person in the back row won't know. To show you are scared you must shout, 'No!' cover your mouth and retreat to the back of the stage.
Involving The Audience
In a normal dialogue the person you are talking to can interrupt if they misunderstand, want to ask a question, change the subject if they are bored. On stage you have to keep them entertained and emotionally involved. They can't walk out in a contest, but they can walk out mentally.
Being Seen At Sides And Backs Of Halls
The bigger the contest and the room where you perform, the more you have to be larger than life in order to be seen by those sitting at a distance, some of who have sight or hearing problems. Thanks to members of the forum for introducing me to a concept known to actors as breaking through the fourth wall (invisible curtain across stage). You cannot sigh quietly or muttering and ignoring the audience at the sides and back of the hall. If you do, people sitting in the back row will start chatting to their friends. Contests have big audiences sitting both sides of a huge hall. To be seen requires 'acting', large gestures, walking about using the whole stage.
But the Top Speakers Are on TV Screens!
Yes, the US president is on huge TV screens. So are the top speakers. But to get to the position where speakers are on huge TV screens (Toastmasters International speaking contest finals) you have to get through the previous stages, without screens, and act.