One of the highlights of Build 2014 was Microsoft's public introduction of Cortana, the digital personal assistant in Windows Phone 8.1. Obviously aimed at Siri in iPhone, Cortana comes with a surprisingly strong list of capabilities. Including, apparently, the ability to make Siri look bad, as a new TV ad ably demonstrates.

As Cortana once famously said to Siri, "It's on, bitch."

In the TV ad, Cortana takes on Siri, as you'd expect. But it does so on an entry-level Lumia 635, a device that will enter the market at under $100 without a contract and will likely go down quickly from there. The iPhone 5S shown in the ad, meanwhile, retails for $649 and up, depending on model.

Beyond the implied price difference—with iPhone, voice control is a feature for luxury devices only—there are some neat bits. Here are some of the voice control demos used in the ad, along with the respective replies.

"Cortana, when my wife calls, remind me to tell her happy anniversary."

Cortana replies, "The next time you talk to Caroline, I'll remind you." Siri? Not so good. "Oh no," she says. "I cannot do that."

"Oh, and remind me to get roses when I'm near any flower shop."

Cortana replies, "Sure thing. Remind you when get to flower shop." Siri: "I can't do that either."

Cortana then delivers an automatic traffic alert, a capability that is apparently beyond Siri. "Now that is a smart phone," Siri says as the Lumia 635 is carted off.

Curious about the obvious canned nature of Siri's replies, I decided to try those commands with my own iPhone 5S. Here's what I got.

"When my wife calls, remind me to tell her happy anniversary."

Siri: "No match found."

"Remind me to get roses when I'm near any flower shop."

Siri: "No match found."

So what have we learned? Not much, just that Cortana—go figure—responds well to the types of questions she's been trained to answer. My gut feeling is that Siri, though in market sooner, is more basic than Cortana (or Google Now for that matter). But Apple or one of its adherents could no doubt make a similar video where Siri saves the day and Cortana comes up short.

Still. Cute.