U3A Photo Challenge

This afternoon I was taking and editing photos for our U3A photo group challenge. I had a mono shot, so thought I'd post it - any ideas what it is? This morning I had to go into town to pick up an order from Boots for something I was told last week they no longer sell, but I found online. I also dropped a few jigsaws off at the charity shop. When I got home I opened the box and only half the order was there - so 20 mins trying to get through on the phone and I got confirmation that despite the text from Boots referring to my parcel, there were actually 2 parcels there (the first one was only about a quarter filled). I also did some tidying up of the pond and surrounding area, finding a frog under a yellowing rhubarb leaf!