。
I never look good in photos.
Literal
I [topic-は] always photo-reflection [subject-が] bad.
写真写り is a fascinating compound: 写真 ('photograph') + 写り ('how something appears in a reflection/photo,' from 写る 'to be reflected/photographed'). Together it means 'photogenic quality' — how well one comes out in photos. The が marks the photogenic quality as the grammatical subject of 悪い ('bad').