There aren’t six shadows though.
Nothing you have said has convinced me that this tiny random thing
Is meant to be an entirely separate character. One that Oda drew much more discretely than the others, and just forgot to draw eyes on, unlike the others.
And that this small random shadow is actually meant to be a giant screaming head
And look, the “six silhouettes” from the previous panel has suddenly went down to five and one indistinct shadow with eyes. Why has the giant apparently disappeared? Why’s Oda hiding Imu’s shape, when he apparently revealed it the shadow before.
In the first page we don’t even see all the way up to the Empty Throne.