The light green serrated leaves in the middle are a hackberry tree that was planted by a bird. They have a bad reputation, but they're fast growing, native, and provide decent shade. If this is at least twenty feet from your house, you could let it grow and have a tree there instead of a mystery shrub.
You can confirm it's hackberry by looking at the veins at the underside of a leaf. You should see three main veins starting at the base of the leaf, similar to if you held up your three middle fingers.
Not art? It doesn't even start with bread according to Irish courts.