My comment on https://www.youtube.com/watch?v=tLlSRFLThYw&ab_channel=SUB-TIL, which no longer exists:
When we desire, we always really desire a certain emotion, to feel a certain way, whether that's happiness, fulfillment, pleasure, satisfaction, joy, terror and suspense (such as by watching a horror film), sadness, or whatever. It's almost a truism that we always want happiness, loosely speaking (in the cases that you want, say, sadness, it's because you relish in the feeling of sadness), and what impetus would we have to do anything if not to achieve an intrinsically desirable feeling or avoid an intrinsically undesirable feeling? Nothing else is intrinsically desirable or intrinsically undesirable for no reasons beyond the thing itself. If it's due to a value, where do you get values come from? Why do we value one thing over another thing? If you trace the whys of anything you want, need, desire, prefer, disprefer, or even do all the way to back to the beginning, you'll always arrive at some emotion or the anticipation of some emotion. So, the object of desire is the thing we think we need to achieve some desirable emotion, or feeling.
The "ensemble" is just the noticing of the fact that the thing we desire is itself not always what gives us the feeling we seek, but the things or situations it enables or that come with it. This is not always the case. In the drinking example, Deleuze was reaching a bit. The person who wants to drink doesn't always care where he drinks; he may just want to get drunk. Though I suppose you could call "being drunk" a part of the ensemble. But when I want to French kiss a cute girl, do I really want anything else but that? It seems not.
I lied a bit. Desire as seeking emotions seems not to cover altruistic intentions/desires, or some other desires such as the drive for pure creative self-expression for the sake of it. I know many people argue that altruism doesn't exist because the person is always rewarded by the feeling of satisfaction from having done a good thing, but I don't agree with that. The reward is not always commensurate with the sacrifice. Love is the reason, and the aims of love, the loci of consideration, are always transpersonal. When we desire to do something out of love, it's not to seek a further emotion; the desire is to accomplish it for its own sake.
But as for other desires, the nature of a desire is that we imagine a way we could feel if we had something, usually based on certain past experiences where we felt that way, and that way is better than what we feel now, so we lament not having the object of desire until we get it. Or it's not always about lamenting, it could be about pure excitement for the opportunity of doing/getting the thing. The fact that we want to seek certain emotions and to avoid other emotions, just based on the intrinsic nature of the emotion itself, is a mystery.
I see Deleuze gets into a little bit about subconscious constructs. What things we know or imagine will bring us desired feelings (and also sometimes what feelings we desire) often (or probably always) depends on psychological factors, sometimes deep, convoluted, imbalanced, ugly, perverse, depraved, neurotic, delusional, insane, and/or conflicting psychological factors, including subconscious ones.
I missed why Deleuze brought up delirium, and I'm not even sure if I know what the word "delirium" there is really supposed to mean, so I can't comment on how delirium may relate to desire.
His talk of the four elements of assemblages seems very strange and out-of-the-blue to me, especially the styles of enunciation part. Certainly, these are factors in some people's desires and preferences at least some of the time, but they're by no means universal, nor are they more prominent than a lot of other possible factors I could think of. I can sort of see his selection of elements if he's thinking of desire in a primarily political context, but that's probably just my imagination.