I was having this same conversation the other day. Have you ever seen that picture where different people involved in the creation of the video game Kirby draw the title character? Two look really good, and the rest are awkward blobs that only look like Kirby because of the power of suggestion.

Anyway, I genuinely think a team of Tesla employees (independent of Musk) were talking about building a truck, and all took turns drawing something while pulling together numbers before the pitch to Musk. As a joke, the design team mocked up the worst sketch in 3D, and Musk accidentally saw the design in the Slack chat history and demanded it.

Either that, or some sort of "have your kid draw the next Tesla" employee contest, and the design teams modeled the funniest ones as actual cars for the company newsletter. Like those companies that'll turn your kid's drawings into real life stuffed toys.