There really is no such thing as a formal presentation or an informal presentation from the perspective of our audience. There are really only two kinds of presentations in the entire world:
And bad ones.
Really. That’s it.
Think about when you are in listening to someone speak or present in front of you. Are you thinking, Wow, I sure am glad this presenter is being formal and grabbing a lectern and standing in front of the room?
Of course not.