S. R. Faruqi:

In the second line there are a number of aspects. Mir is wandering around apart because he is lost in the thought of meeting with the beloved. Or because secretly, alone, he wants to meet her; and again, to wander alone is a sign of displeasure/discontent. Or, again, because he's lost in his usual thoughts of union with the beloved-- that is, he has no intention or scheme for meeting the beloved, he has only an absorption fixed in his heart: 'let's see when we would meet her; would we meet her or not?'. That is, in the first situation there was a sense of a scheme, an intention in his heart that he would go and meet her, and when he would meet her, what delightful affairs there would be. In the third situation there's only a half-baked idea that somehow he would meet her.

The wordplay of judaa judaa and milne is also very fine. The speaker is not Mir, but some other person (it's possible that it might be the Rival or the Advisor). It's a verse in Mir's special style.

FWP:

SETS == OPPOSITES
MOTIFS
NAMES
TERMS

Someone else is observing Mir's behavior, and asking this question-- but we have to decide for ourselves in what tone he's speaking (suspicious? wondering? compassionate? sarcastic? amused?). We also have to decide whether the question is rhetorical (the speaker implies that he really knows very well why Mir is wandering alone), or genuine (the speaker genuinely doesn't know whether Mir might have some other, unknown purpose instead). It's a maximally, and most effectively, insha'iyah verse.

Note for grammar fans: Nowadays kisii se milnaa would mean 'to meet with someone', kisii ko ko))ii milnaa would mean 'for someone to encounter someone', and kisii chiiz kaa milnaa would mean 'the obtaining of something'; this latter form is rarely used for human beings. But patterns like these may not have been so established and so differentiated in Mir's time. Or else the crazed lover might indeed have been dreaming of romantically or erotically 'obtaining' the beloved.