Possible Clues:

• Like the opposition, present without notice
• Dog needing publicity entered in Cruft's, perhaps
• How the pig had got in in the shade
• Dark area, weak remnant (of something)
• Image caused by obscuring of light
• Trail programme with commercial break?
• This cabinet is in opposition
• Mere semblance
• Crufts, say, holding short display for dog
• Follow commercial that's interrupted performance