In his must read book, Influence: The Psychology of Persuasion, Robert Cialdini explains that people are prone to trust taller people more than shorter people. So, size does matter after all.
Regardless of how tall you naturally are, you can do a few things to give you the trust (tall) advantage. When filming video or Skyping, position the camera to be a little below you, so the picture is taken at an upward angle. When taking photographs and headshots for your website, business card, or brochure… do the same – a slight up angle. And if you are meeting people face to face, wear shoes that make you taller, and always… always, stand-up straight. Mom was right.