Sand for the statue and fences for protection.

Not for a particular king!
No.
Not even for kings in general.

Only for all those ‘in charge’!
As a reminder for the fact that their authority is very fragile.
Goes for only as far as it is accepted. Protected by those who respect it.

As a reminder for the fact that fences not only protect but also separate.

The point being that whenever those calling the shots no longer suffer the consequences, the situation becomes extremely fragile.
That whenever a ‘king’ needs to be protected from his subjects instead of by them…