[Congrats, you are haunted!]
If someone ever ask him how does it feels being a ghost, without any hesitate, he will tell them that it actually quite cool. In a way, he is immortal, because while dead and a ghost, he still there, float around the world without a care that he will be attacked or killed by them, not that they could see him, unless he chooses to do so.
Years after years absored nature chakra, Itama has managed to creat a chakra form for him, in other word, a body like when he still alive and even able to use chakra, but it won't last long, after all, he is dead and that just a small trick he learnt. Another cool thing is he can move things, nothing strange, any ghost can do that anyway.
Back to the current situation, after his brothers's dead, Itama still hasn't able to move on and he just kinda travel around the world like that. He still return to his brothers's tomb, unwilling to let them be there without anyome to guard them, but at this moment, he is on his trip again - which proved to be quite a good choice, seeing he just come across an Uchiha. Her chakra is a dead give away, but he wouldn't be so sure. Though, he believed he has saw her before when visited Konoha.
And so, with all the time in the world, the ghost just... Decided to haunt the poor kunoichi. Until it is time for he to go back to his brothers's desd bodies. But yes, Congratulations, Yuukoro now haunted by a Senju Ghost!