Can someone explain this?

[u/Pretty-HAHA]

It is possible this man has suffered brain damage from huffing the Elmers glue fumes needed to construct this sign, (+1 for giving his own artwork the double finger...edgelord move for sure), but can someone explain this to me.

What is the witty joke this man is making?

[u/allhailmillie]

I believe drawings or sculptures of ducks were considered to bring good fortune. Many stores excavated in Pompeii had dicks and such drawn on them.