Why is this funny to a Dutch person in particular?!
It's a few things, drop is the word for licorice and lol is the word for fun. It's also one letter off 'droplul' which would be a swear word for asshole, literally: licorice dick.
The domain licorice.fun is available!
Drop is our national licorice candy, and lol means fun (not just as the acronym).