With Luna and Uriel gone, all Medusa wanted to do was to spend the day inside the workshop. All she could think of these days was to remain shut inside four walls and as far away from other people since she still couldn't control her trait. But the possibility of hurting innocent people wasn't the only reason she wanted to be alone, she wanted privacy to silently cry the passing of Nika without anyone noticing.
No matter what Uriel said, Medusa still believed Nika was actually dead and she felt a part of her soul dying every time she had to pretend everything was fine. It got to a point where even inventing new gadgets didn't bring her much joy and she only used it as an excuse to distance herself from her friends.
At least while she was working she didn't need to wear that blindfold since no one was supposed to interrupt her while working.