One page from Power Girl #5
The source has the preview for Power Girl 5 up.
Shoes? They're for sissies, boys and girls. You thought Superman was tough? Think again.
Contextual reason (i.e. the uncool reason): She accidentally left her shoes at her office, along with her gloves. And decided to fight without them. Because she's awesome. (Also, she has really nice feet.)
recommended tags: char: power girl/kara zor-l/karen starr, title: power girl, creator: amanda conner, creator: jimmy palmiotti, creator: justin gray