Internet slang from the BBS/Tieba era (~2010s), built from 爆 (bào, to expose / drop a bombshell) + 照 (zhào, photo). Standard request on forums when an anonymous poster's appearance becomes a topic. Casual only — never formal.
memory
Think of 爆 as 'drop' (as in 'drop a track') and 照 as 'photo' — drop a pic. The 爆 implies a small reveal-event, like popping confetti.