I cannot say what the avatar means to Night, but I can say what I see in it. Night's avatar has deep meaning and deserves focused attention.
Emperor, your sword won't help you out
Sceptre and crown are worthless here
I've taken you by the hand
For you must come to my dance
I had to work very much and very hard
The sweat was running down my skin
I'd like to escape death nonetheless
But here I won’t have any luck
No matter how hard our ego strives for in this life, in the end, we're purified in the fires of death and renewal.
Mortificatio, a purification cycle not only of nature, but of the inner psyche where dying makes room for beneficial growth and new ideas. Death and regeneration of the self. To me, there seems to be a trickster element in the avatar's expression as well. It is our own actions and resulting Thanatos against the toxicity we create that brings death to us, no matter how hard we try to fight it. We invite it with our alienation from self, the Danse Macabre of acting in ways that split us off from our truth. Because of this, we're reeled in no matter what, our severance from all that we create here waits for us, not so much as a punishment but as a cleansing and renewal.
"Mankind’s *self-alienation* has reached such a degree that it can experience its own destruction as an aesthetic pleasure of the first order" - Jerry Mander
Don't fear change for in change and renewal our best yet may come forth.
EDIT: The clock set at five minutes to the hour represents the tension in the situation, the urgency for change, to make a decision. The trepidation of the hour of our reckoning coming forth. The juxtipostion of the foreboding clock and the relaxed, happy face of death is also a telling message. Death knows we're coming, he can patiently wait.