He wasn't the person she'd spent that time with, she knew. He hadn't invited her to meet his daughter and share space with them, he hadn't helped her piece together her broken parts when she came back more mangled than she'd meant to. But hearing him say that he missed her, she allowed herself the illusion that he was. That in the time since his death he had missed her.
It was foolish of course, Nebula knew this. But she had learned that emotion sometimes relied on foolish illusions, on hopes for things that had not yet happened. And she couldn't help the surge of it then as he looked at her.
"I've missed you too." Said quietly, holding back the full weight of what she felt because it was not his to bear, but she would have wanted to say it to him if he was the Tony they had lost. She missed him, and she missed the future that he would have had, and the chances she would have had to know him more.
"Come with me," Even just to look, she wanted that, to have more of this however fleeting it might be, before he was gone again.