Look at the bottom-right gif. He’s crying. :c
It looks like he’s going after Thor in whatever way will hurt the most. If Thor were attached to something or someone else, Loki would threaten them/it in order to cause Thor as much pain as possible. It’s not about Jane at all. He’s just trying to get a rise out of his brother.
Honestly, I’ve done that. I was furious, sad, and knew exactly which phrases would do the other person the most harm. I took it upon myself to say them all. I thought it would make me happy. It didn’t, and I realized that as I was speaking, which led to… well, it looked a lot like that gif.
No wonder Loki’s crying. Rage, loss, betrayal, probably guilt somewhere in there, too- he’s basically experiencing every negative emotion at once, and he’s trying to put Thor through just a little of what he’s going through.
IF YOU EVER HAVE ANOTHER LOKI-RAGE MOMENT, I SHALL GIVE YOU ALL THE HUGS YOU NEED. JUST COME TO MAMMA VAL.
In the meantime, we can cry together at the completely human anger and sadness that Loki is going through.