The paper currency in the Seychelles is so beautiful (when not crumpled – grins) many travelers save the smaller denominations as souvenirs.
The images feature nature and landscapes.
And I thought it was great that locals and visitors are reminded of the importance of nature whenever they use the currency! Maybe it will cause them to think more intensely about their purchases and about how those purchases impact the environment around them.
Currency here on Earth and in our fictional worlds often reflect what that society values.
An authoritarian regime, for example, would have an image of the authority figure on their currency. A rock-loving society would have images of great rocks on their currency.
Sharing little details like the images on currency can deepen world building and draw readers more fully into our stories.