Analysis of Upon His Picture

When age hath made me what I am not now,
And every wrinkle tells me where the plow
Of time hath furrowed; when an ice shall flow
Through every vein, and all my head wear snow;
When death displays his coldness in my cheek,
And I myself in my own picture seek,
Not finding what I am, but what I was,
In doubt which to believe, this or my glass:
Yet though I alter, this remains the same
As it was drawn, retains the primitive frame
And first complexion; here will still be seen
Blood on the cheek, and down upon the chin;
Here the smooth brow will stay, the lively eye,
The ruddy lip, and hair of youthful dye.
Behold what frailty we in man may see,
Whose shadow is less given to change than he!