Many other proposals for flags of Mars focus on just one aspect of Mars — either the fact that it is the fourth planet from the Sun or that it has two moons. Again, I think that the flag should represent more than that. Other flags are based on the astronomical symbol for Mars, ♂. This is unsatisfactory for two reasons: first, this symbol doesn’t relate to any feature of Mars or of humanity’s relationship with Mars (instead, it’s based on the shield and spear of the Roman god Mars), and second, this symbol is also used as the male symbol, which would likely lead to misinterpretations.
One other benefit of the new flag, which many other, more complicated, proposals do not have, is that the basic elements of the flag — the red chevron on the white background — can be adjusted to work in many different contexts outside of this rectangle.