The word ;Daa;Nk has been used as both masculine and feminine. [A discussion of why in this verse it must be masculine, and the difficulties of various dictionaries with the word.]
With regard to ;Daa;Nk , the second point is that it has been variously spelled ;Daa;Ng , ;Daa;Nk , ;Daak . [A discussion of how based on usage,;Daa;Nk is to be preferred.]
The third point about ;Daa;Nk is that usually its meaning is given as 'a leaf of silver or gold that used to be put beneath a precious stone [in a ring or other setting] in order to increase its glitter'. In some dictionaries, a leaf of copper too has been included. There's nothing wrong with this definition, except that ;Daa;Ng / ;Daa;Nk / ;Daak was used for every small fragment of glittering foil, and these used also to be attached to clothing for adornment. (In English they are called 'sequins'.) In the urduu lu;Gat taarii;xii u.suul par one meaning given is 'a kind of fabric', which is entirely wrong. The fact is that garments on which ;Daa;Nk were attached by way of adornment were called, for example, ;Daa;Nk kaa angiya or ;Daa;Nk kaa jo;Raa . [Several verses by different poets are provided to illustrate this usage.]
In the present verse, the first point is the rareness/uniqueness of the simile and the image. In order to express the glittering and redness of the face, to take the face to be a ruby, and the redness of blood to be a ;Daa;Nk of flame, is a masterful accomplishment of insightful imagination, and of creative feeling for colors. Among us, for someone with a very red-and-white complexion we say that 'blood drips from his/her face'. Thus to use for such a person the simile of a ruby with a ;Daa;Nk of flames beneath it is a very fresh idea.
But half the beauty of this verse is in the 'dramatic' style of the second line. He hasn't said that the beloved's face, or the color of her face, glitters like this. Rather, he's said that 'We've seen the colors of faces glittering like this'. Now both a generalized expression of human beauty has been made, and the insha'iyah style has also brought in aspects of praise and amazement and joy. The simile of a pure ruby for the glitter of the color of the lips has also been used in
and an insha'iyah style. In addition, in that verse several other things are mentioned through which the whole verse gleams with a red light. In the present verse only one lamp has been lit, but the light of that one lamp is showing its glitter on the faces of all the beautiful ones. Then, in it the assertiveness of the speaker's voice is also blended, as he boasts that he himself has seen such faces and such colors!
The question has been left ambiguous as to whether the faces referred to always have that color, or at moments of joy, or anger, or rapture such a color comes over them. The tone of the verse is such that it seems that to bring such color to those faces is also an achievement of the speaker's, and perhaps it is on this basis that the boastfulness too is excessive.
So adorned, but so light/swift of expression; and so brimful of a sense of physicality, but so far from any cheap pleasure-giving effect-- such verses only Mir can compose.
In the fifth divan Mir indeed has composed a verse with a rareness of theme that to some extent makes it a reply to the brilliance of the present verse [{1543,8}]:
baat karte jaa))e hai mu;Nh tak mu;xaa:tib ke jhalak
us kaa la((l-e lab nahii;N mu;htaaj rang-e paan kaa
[she goes on conversing, the radiance is as far as the speaker's face
the ruby of her lip is not in need of the color of paan]