You can also make a region longer by dragging its right end to the right. That’s not the same thing as dragging the top right corner, which makes the loop loop. Instead, dragging the loop’s right edge extends the loop’s width without making it repeat.
You might wonder what the point is, since the extended area of the region is filled with silence. Well, this trick can be handy when, for example, you recorded only seven measures, but want to loop the region so that it repeats every eight measures. By making the region an even eight measures long, you can now drag its upper-right corner to make it loop evenly.