They show a friendly, welcoming persona. Just as a circle concentrates its strength at the centre with weaker forces moving out from it towards its soft perimeter.
Martin Licis is the new 2019 World's Strongest man and a round human. His friendly nature, strong heart and body compares favourably against many gym bodybuilders focused only on their superficial muscular exteriors. People with superficial priorities display a no heart mentality. Exactly how a square shows border strength and empty interiors. Protecting the brand because the heart is missing.