Catlateral Damage: Remeowstered

It's going to seem counterintuitive, but the fastest way to complete this is to just keep playing. I got a huge chunk of them in procedural mode pursuing a different achievement. Fulfilling objectives is the main way to get photos, but some appear in frames in actual levels, including procedural levels. If you're thorough and try to knock everything over, you'll get any photos found that way, and if you make sure to prioritize your objective items, you'll get photos that way too.

It may help to manage your energy by going one room at a time. I personally prioritized levelling up my energy meter first as well, but that may not be your prefered way of going.