Does "Somebody’s The Dog, Somebody’s The Pony" mean "somebody's slave/servant"?

Context:

Esquire magazine’s overblown rhetoric misleads on Keystone XL
A June 19, 2014 Esquire Magazine blog entitled, Somebody’s The Dog, Somebody’s The Pony, contains a number of factually inaccurate statements about Keystone XL.

Pipelines are necessary and critical infrastructure that not only protect public health and safety but are also the primary delivery method for the majority of energy products that hundreds of millions North Americans rely on every day. Describing responsible, state-of-the-art energy infrastructure that helps power the U.S. economy in the manner Mr. Pierce does is a disservice to those trying to encourage greater energy literacy.

The claim that oil sands production “is the world’s worst fossil fuel” is false. The truth about oil sands derived crudes: they are well within the same range of greenhouse gas intensity as nearly half of all oil currently refined in the United States and have lower GHG intensity levels than oil produced in Venezuela and California. It is also widely known that GHG’s from coal-fired power vastly outweigh the emissions from oil production. In fact, the entire oil sands industry, which employs nearly a hundred thousand people and contributes billions to the North American economy are equivalent to 4.3 per cent of coal-fired power in the U.S. alone.

More:
http://keystone-xl.com/esquire-magazines-overblown-rhetoric-misleads-on-keystone-xl/