To put it short, here's the pro-s.
Composition and the dynamism(s). The latter are on-the-brink-of-minimalism.
So to say, the scenery of an event (a walk in the street,) is seen through a keyhole!.. yet it is in a shape that is core (check the title.) A viewer's perception fleets easily, from the dynamism on a top part of that shape, to the dynamism below (lucky we don't trip over the dog... Or do we, in another sense?)
P.S. The work finalizes by funny. As ECharlesWhite has pointed in his review, "Cute and chubby," and the dog's nonchalantial expression.