It doesn't make any fucking sense. At the beginning of the chapter, Ashida says that he configured his device so that it could pick up vibrator's signal, yet the other device was able to pick it up from the start along with tablet's signal? The only way it could happen is if her tablet's signal had the same frequency as vibrator's signal, but then Ashida's remote would also work on her tablet.
Again, it doesn't make any fucking sense.