Possible Clues:

• Alter (a photograph)
• It's used to enhance a photograph
• Touch up
• Alter, in a way
• Touch up inflamed rash and bruising, half concealed
• Adjust picture for broadcast on skirmish
• Artist's device; conceal
• Painter's last to board plane and he's first to touch up picture
• Conceal details of minor collision between planes?
• Look before groom gets to tone down photograph