What are you talking about? He always acts like this, so him being aggressive in your dreams just means you’ve grown accustomed to it, though are no less susceptible. It’s also really cute that she’s dreaming of him to the point where she’ll change how she does her hair to make Sakamoto happy.
Though we all know he loves her no matter how she looks, so it doesn’t make much of a difference. It’s the thought that counts after all, in this case literally.