Miranda Lambert does make an impression wherever she goes. The country star is the guest judge on a new episode of fashion-designer competition Project Runway that starts airing Thursday night (Feb. 21).

In the promo video, Miranda, in a fancy black dress, tells a contestant, "Doesn't look like I could squeeze a spank under that," a reference to body-slimming Spanx products.

The episode debuts at 9 p.m. ET on the Lifetime cable channel.