I was working with a client once (no not the guy in the picture) who was just a lovely, lovely, lovely man. And guess what, when he presented, he came across as simply lovely, lovely, lovely... smiled loads, light and fragrant almost and... minimal gravitas.
He was super bright, and his organisation saw him as a future leader. However, he didn't get many opportunities to present and so shine to the wider senior leadership team. In truth this lack of gravitas was the reason why, and of course the fewer times he presented, the less confident and more smiley he became.