When I'm looking for images the following things are important:
- landscape or portrait (nice to have one of each)
- photos which are not too dominated by helmets and hi vis (while reflecting the reality of cycling in the UK)
- pictures of kids where the child isn't identifiable are always useful, as sometimes parents are a bit startled to discover their nipper on the front page of POP (apologies!)
- shots that manage to capture the magnitude of the crowd at both ends
- nice, sharp well-composed pictures of each of the speakers
- plus a scattering of 'typical PoP' shots - someone in costume, home-made signs, improbable bikes, dogs, kids, trailers etc.