"It can be hard to tell exactly what you like and what you feel indifferent to." < - I suspect this is true of me at times.
Susan's basically referring to the room in her purse in panel one. She can easily transport one in with no risk of her mom noticing, and she might be a ble to fit a second one in there, but four? As a wise person once said, NOPE.
I suppose that could be many wise people. And not so wise people. A lot of people say "nope".
I fully admit, and have admitted, that I wound up with some writer's block in regards to this storyline as a result of going off on a "oh hey, I never explained the feedback Susan gets from the dolls" tangent. It left me somewhat unsure of how to transition to them actually being done in the basement, and I kept thinking of more things I wanted them to do prior to leaving.
As such, this comic is sort of meta for me. Nanase can think of all sorts of more things they could do to the point where she's ready to try and change the plans she had, but Susan's putting a stop to it and finally getting them out of there. Thank you, Susan.