Ladybird, Ladybird ...

On a lovely day we were enjoying our coffee on the deck when I noticed this 7-spot ladybird. I was keen to get a photograph but she wasn't in the mood to co-operate. I left her alone but kept an eye and eventually she quietened and I flopped down to get an eye level shot. It was what happened next that puzzled me. She (I say she but I've no idea) raised her nether portions against the leaf. What's that about? My extra is a photo of the behaviour.