Have I just noticed something?

Well. I’ve not SEEN this mentioned – yet – though it may be well known.

A cutting of the Bronzino Allegory of Public Happiness has just shown me something that I’ve yet to see explained.

See image above.

Folly Defeated.

I noticed the Jester Cap. The bells around his leg but…But…BUT…NOT the huge NAIL that he holds in his right hand.

Can anyone explain?