The correct choice is 'だったので' (from 'だった' [past of だ] + 'ので' [because]). The context indicates a past reason: '...the photo was very beautiful, so...' Since '綺麗' is a Na-adjective, the past polite/plain forms are followed by 'ので' as '綺麗だったので'. 'だからで' is grammatically incorrect in this sentence structure. 'なばかりで' and 'なはずで' do not convey the simple causal past reason.