This particular level and visibility of sky writing is new, but "drawing things in the sky" dates back to the 1920s or so. That sort of skywriting uses oil to cause the airplane to leave a trail of white smoke, visible against the blue background of the sky.

The precision we see in this route is fairly new, but, especially on proving flights for new aircraft, which needed hours and hours of flight time and would take off and land at the same airport, and even before the public could see it on a website, filing flight plans that contained (much cruder) drawings of "747" or otherwise certainly exist.

Drawing stuff on a map with a GPS track is a rather beaten path in the world of Strava and similar [0]. Not being bound to the road network graph just makes it easier. I don't want to think about the fuel burned for this stunt, but if I were in some position that is required to sign off that flight path I'd sure congratulate whoever came up with this. Wouldn't even be all surprised if tomorrow some Airbus ferry flight would respond in the same medium with a respectful salute to the old lady.

([0] but relative to anything that would be considered a tradition in aviation, the entire concept of GPS is rather newfangled, despite it's surprising age, I'm not disagreeing)

On a much smaller scale, it has been around for a long time:

http://wbcnthefilm.weebly.com/film-blog/who-ever-heard-of-a-...

I don’t think it is. Boeing has been doing it for years. They did it in 2014 for sure and that wasn’t new. That was nearly a decade ago.

Skywriting seems visible to me? This is just an evolution of the same idea. This is a Looney Toons gimmick.