The ushin shapes came from common symbols:

 
     Needs – the triangle harkens back to personal growth and development pyramids, such as Maslow’s Triangle of needs:

    Feelings – the heart is intuitive, a common emoticon.
Real heart human heart clip art hostted 2 clipartbarn
    Thoughts – the thought bubble, an oval
Thought bubble clip art free clipart kid - Clipartix

    Facts – the square represents documentation, e.g. proof

    Merits – the star typically represents merit, the number of points in the ushin star stands for the 8 shapes.
  People – the banner, or self-representation of person or group
  Actions – the directional arrow points out the “next” action
    Topics – the open-top trapezoid represents the all-inclusive bucket
HQ Bucket PNG Transparent Bucket.PNG Images. | PlusPNG