The design is based on this style
of airplane bathroom sign, which I believe is standard on an Airbus A330. Since we have a cute Hipmunk mascot, I had to include him. And while two Hipmunks on the sign tilted each direction might be ultra cute, Hipmunk was founded by the same guy who made Reddit, and so the Reddit alien was an obvious choice for the second figure.
Using the picture as a reference, I traced the sink and mirror pattern from the original sign and the Hipmunk mascot, then found a vector version of the Reddit alien and assembled them all together into a 15"x8" rounded rectangle.