Hate this dress. Hate hate hate it. It's not flattering, it fits her weirdly, and why on earth is she wearing a sparkly, low-cut dress in the middle of the day?
I think it's photoshopped, otherwise it makes no sense and it looks odd (not only the dress in that time of the day, but the edges of kate)
This was during the 2007 break up - when she started to get scary thin and was out every night to show Willy what he was missing. It's an evening shot - in the UK in summer it's light till almost 10pm. I think it is dusk in this photo so the photographer has used flash and she looks like she has been photoshopped in.
I think Kate thinks photos like this are what won Willy back so she has to keep up the long hair, glamour and skinniness in order to keep him. If her post baby body is not exactly as it used to be eg her boobs have dropped a bit I imagine she could become majorly insecure since he has never seemed overly devoted to her.