What is this missing bit off a parcel shelf?

[stokefan]

Hi all,

what is this bit missing, and will it matter?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=4605655143&fromMakeTrack=true

[Arnold]

For four quid, you cant go wrong, especially if it means saving your own one from getting the chop. The bottom right corner could easily be repaired if it plays a critical role. Remember, the original shelf would need re-inforcing to make the most of the speakers you've stuck inside there, and will give the carpet a firmer base on top