Hello!!! I dont remember so well how to do the PV star, but I can help you with the image, it's the fifth shadow star.
To get this you must do the shadow route and before the part where he covers your eyes, exactly just when you leave your room and you are like in the main room, I don't know if I understand myself. Well, you must touch the upper right corner, near where there is like a staircase. Touch near there because the place is not so exact. Doing that will take you to another room... and you will get a bad ending but that's the route.
Oh! I don't remember how you get to this part, but it's the route where Ginger discovers that they hide Shadow and fight. From there PV leaves and we are going to console him while shadow was tied up I think...
On that route in the part where they are talking to ginger and vanilla, after that conversation and before going to help, you must touch the blue store, to buy the chocolate. And from there at the end you must offer them to vanilla while you console him.
Sorry if it's wrong, but I don't remember so well...I hope it works for you ;3