Related Clues:

• Admirer from afar, maybe
• Window shopper, essentially
• Peephole spy
• One watching
• One having a look-see
• Gazing sort
• Watchful person
• Surveying sort
• Register surprise, facially (and just barely)
• React, barely
• One who eyeballs
• One using binoculars
• Gander-taker
• Person who is looking
• Watchful one, really