Miku is an android made to be a synthetic pop star. . . however, instead of a docile, pre-programmed machine, her creators went a wee bit overboard and made her a full-fledged AI. 

If she were evaluated by human psychological standards, she'd probably be considered sociopathic. She's quite a troll, deliberately pushing people's buttons so she can see how they react and add it to her database. Or, well, that's her excuse; it's pretty plain that she also finds making people a bit uncomfortable rather funny, especially if it's Homura. She's very flirtatious and is what can be best described as "omnisexual": doesn't matter if it's male, female, hermaphroditic, agender, or a giant mysterious questionmark, it's all equally intriguing to her. 

EVERYTHING. But skimpy, ridiculous, or sparkly is a bonus. The more bonkers, the more likely she wants it. 

Singing, trolling, livestreaming the camera feeds from her eyeballs with no explanation