From the description on that poster
"The artist’s share of profits from sales of this poster will be donated to NASA."
How, Though? You can't donate to NASA
"The artist’s share of profits from sales of this poster will be donated to NASA."
How, Though? You can't donate to NASA
The rules are just a rule of thumb that we can apply evenly at scale to avoid corruption. When there's legitimately no corruption happening the rules get more flexible. If it ever becomes an issue HR will frown (because rules) but legal will apply the duck test and conclude that ~$10 pizza/person paid for by someone who doesn't need/want/isn't in a position to benefit from preferential treatment is not corruption.
Details of the NASA budget can be found at the inevitable Wikipedia page: