Images with variable dimensions (scrambled [jit.pwindow]s)

Hello. I'm brand new to jitter and i seem to keep getting scrambled displays when trying to load images (only jpgs right now, no video), like the one in the pic i've attached. I feel like it's maybe because the dimensions of the images are way different from what i'm specifying as attributes for the various jit objects i'm using (although i've tried different dimensions and sometimes it works sometimes it doesn't.) If so, how would one be able to display any image, of unknown size? If not, what am i doing wrong here?