Why does there seem to be a halo around the figures?
As the label might already explain, this is a fragment of a larger work originally titled "In the Park." After this piece was cut away from the original work, it was re-cut into an oval.
Then those "spandrels" (triangular additions to the corners) were cut from another piece of canvas and added later. Weir painted them to fill out the composition into a rectangle again! He matched the colors on the spandrels to the colors resulting from the dark varnish that was on the original composition. Because the varnish was later removed, we're left with a lighter oval center. Complicated, right?
Makes sense but yes, complicated!