First, I have to give Mr. Pernefeldt kudos for actually creating and proposing this flag. As an avid science fiction reader, the idea of humanity united under a single flag is not a new idea, but to see an individual actually propose a world flag is, in my opinion, a great step towards realizing that vision. As the world sends probes, satellites, rovers, and lightsails out into the galaxy, the necessity of a unified world flag will only become more conspicuous in the eyes of the Earth's inhabitants and it's leaders. I am not a big fan of the idea of this particular flag representing all of earth, I do think it meets some of the necessary criteria for a flag. The most important criteria would be that it should represent how earth is seen from far away, and the royal blue color accomplishes that nicely. Another important criterion is that the flag would have to be abstract enough so as not to exclude any particular groups, whether human, animal, or natural. This flag is sufficiently abstract enough to be all-inclusive.
For all the hype around the flag itself, the idea behind this flag is what I find most interesting. Mr. Pernefeldt's design has brought, if only indirectly, the notion of world identity to the forefront of our minds. Barring the idea of how a flag would represent Earthlings to aliens, this effort is partially an effort to look beyond the superficial boundaries of nation, ethnicity, race, culture, religion, and instead create a world identity. To connect the people of this world to each other through the understanding that we all inhabit this tiny blue dot in a vast cosmos. We all have a share in this world, and that realization can help us understand each other, if only a little bit better than we do now.
I end this post with a simple message. Think about how you are like every other person on the planet, and how that identity could be formed into a species identity, for ourselves, and for the world.
Thanks for letting me ramble,