Cool - it's just a big scary nothing then.
When I saw the red on its butt I thought wow that can't be not good. I knew it wasn't a funnel web as I had plenty in the house when we had the brick work exposed upstairs when building the extension. They don't back off, they just face you with their legs up in the air when you tease them with a wooden broom stick. I had one that jammed its fangs in the wood once and I had to shake it off.
You wouldn't like to be bitten by one of these for sure. That's gotta hurt.