Frowning Spider

I was passing the pond looking for something to photograph, there was lots of blossom falling in the pond due to the wind and at first I thought this white spec on one of the flowers was a piece of blossom.......until it moved on it's web to another plant.
Looks like he doesn't want to be photographed, as I got closer he started posturing I think to warn me off, also he appears to be frowning (but maybe he always looks like that)