We will be looking at applying early next year so have started looking into the requirements.
On the back of the application form it clearly states which documents you need to supply.
Regarding the finances, it says:-
Evidence of your finances. Bank statements, building society savings books, pay slips or other formal documents as evidence of your and your partner’s ability to maintain and accommodate yourselves and any dependants without recourse to public funds.
It does not say that you need to provide any pictures, by providing the letters in both your names is all they need.
Good luck in your application