Samsung Sam - Sam by Telepurte

Hey, stop shaming me! LEGO is a perfectly valid hobby for an adult.

Oh yeah, it's used for all kinds of things that would be inappropriate for children, such as:

LEGO Sesame Street
LEGO Winnie the Pooh
LEGO Spider-Man

In all seriousness, it's just a label they use to indicate more advanced builds (it was previously 16+). It is a sign that it's oriented on adult collectors, but is in no way meant to forbid children from enjoying it as well (unlike something like porn or alcohol)