The Microsoft ad shows Siri on an iPad Pro, throwing a party to celebrate the fact she now has a keyboard. Sitting next to her is Cortana, displayed on Microsoft's Surface tablet.
"I'm a computer now, just like you," Siri tells Cortana.
Cortana then grills Siri on whether she has other computer-like functionality, such as a powerful processor, the full (rather than app) version of Microsoft Office and a trackpad and external ports.
"I don't like where this is going," responds Siri. "Maybe this party thing wasn't such a good idea."
The ad appears to be a tactical response to an Apple ad released at the beginning of this month titled: "iPad Pro – what's a computer?".
Tablets, and particularly Apple's iPad, have long been seen as inferior products to desktops or laptops when it comes to productivity. Apple's original spot points out the usefulness of iPad Pro's keyboard and the Apple Pencil.
Still, Apple might have the last laugh. According to April figures from IDC, Apple's relatively new iPad Pro is already outselling the latest version of Microsoft's Surface tablet.