Bitcoin stamps are like the crypto version of merit badges - you collect them to show off how much of a Bitcoin badass you are.
Essentially, Bitcoin stamps are unique pieces of digital artwork that can only be owned by people who meet certain criteria, like holding a certain amount of Bitcoin for a certain amount of time.
They're kind of like the grown-up version of those gold star stickers your teacher gave you in kindergarten - except instead of putting them on your chore chart, you put them in your cryptowallet to impress your internet friends.
Example
"Bro, check out my new Bitcoin stamp! It cost me 1 BTC and my left kidney, but it was totally worth it."