This is what Miranda will say if the following conditions are met:
1. After you do her loyalty mission, go to her and talk. She thanks you. The dialogue choices you select in this conversation have no impact on future events.
2. Converse with her again. This should be the conversation in which she apologizes for underestimating you; it is also the conversation in which you can initiate a relationship with her. You can either say she's hard to compliment (paragon) or accuse her of being jealous and kiss her (renegade). Each path will result in different entrances to the second conversation with her.
3. Avoid speaking to her again until you have an established romance with either Tali or Jack (i.e. they have no new conversation options after missions are completed).
4. Go back to Miranda and talk. What she says depends on how you handled the first encounter. If you chose the Paragon dialogue options, she will say "Everybody on this ship needs to know you're mine." If you chose the Renegade options (and kissed her) she will say "And if you think anything like that's going to happen while you're doing the same with someone else, you're very mistaken."
For this specific video, I was already with Tali.
PC version of Mass Effect 2.
Screenshot of face if you're interested: [ Ссылка ]
