(1) Correct proportions of the distances between objects (namely the planets, planetoids, and the Sun), and (2) the correct proportions of the objects themselves.
The links (A) http://www.solarsystemscope.com/ and (B) http://space.jpl.nasa.gov/ show correct proportionality in DISTANCES BETWEEN OBJECTS but NOT the objects themselves.
For correct proportionality for both the distances and the objects themselves, see http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.h...
The problem with http://codepen.io/juliangarnier/pen/idhuG is that both the distances between objects and the objects themselves are not proportionally correct.