The question will be very clear about what it is asking you to do. For example, this year:
Do you see how part (b) says how the you 'incoroprated the provided image to create meaning'? In this case, you don't need to reference your prescribed texts, but instead the stimulus. You only include 'quotes' from your prescribed text if the question asks for your prescribed text.
I didn't either. Glad it didn't ask cause i didn't have that much prepared by way of prescribed texts, but I had some good analysis of my own piece ready.