The low privet hedge to the right of the block paving, central and towards the foreground. I'm going to say the dark shadow outline on the block paving differs subtly in shape between the two pictures. Caveat - this might, however, be an effect of the lightness contrast between the two photos on my 'puter, and not necessarily an actual difference …...
I think I may have it. On the fence there's a sort of post sticking up with a cap on top of it. Below that there seems to be a rectangle of light in the first picture which is absent from the second? It's sort of like in the second picture the stem of the post has disappeared? Or summat ….