Thommango

So I followed the instructions for transforming a pixel selection and tried it multiple times, but I must be missing something. Here's what's happening: I have a single layer with some content. I make a marquee selection. I press Q. The screen outside the marquee goes monocrome. I press V. Handles appear on the selection. I drag a handle. The selection changes. However, my expectation was that the content would be stretched. What am I doing wrong? Thanks in advance.