Then I thought, wait, they are located in SF, and are clearly aiming at the art-savvy audience, who would immediately make the connection between this ad and the Obey Giant.
If you don't happen to belong to this dogsitter's target audience, let me clarify. Here is the "Obey Giant" iconic image, created by Shepard Fairey (of the Obama "HOPE" poster fame). This image has adorned (or disrupted, if you are so inclined) many a cityscape as it became an international collaborative campaign between numerous street artists.
Anyways, now that you know what it's about, the dog ad makes more sense, dunnit?
Now the question is, why target the art-savvy group? Is it likely that those type of folks will have the disposable income to spend on a dogsitter? Presumably they did their research and this really is the niche that's going to pay off.
Have to admit though, it's very clever. Hopefully not too clever for its own good.