'image' is a pretty broad concept and and since currently there is no need to tie ideas together with a common theme it won't matter what kind of texts u use: music, architecture, paintings, novels, plays - theyre all texts.
technically it wont matter if u borrow from your friend's notes and chosen texts either - (who else is going to know or care?). on the other hand they might seem impressive but just hope s/he understood what the module is about.
the important thing is that you need to understand the work rather than just repeat it to eventually answer the HSC question directly and access the highest bands. try applying your friend's understanding to any 'significant' text (one that tries to make a statement) that u find and see if u can explain how it shapes meaning and responses through techniques- and why (that's a context thing - do some quick research).
a common theme gleaned from the truman show such as 'agendas' may be useful and using media texts (say, a display ad and a newspaper or magazine article) may help u tie the three texts more closely together. this will give u scope to evaluate what is going on rather than just state it, which should gain u more brownie points. in the end, the choice is yours.
good luck!
2-3 would be fantastic!!