You can set the editors display options in this panel.
With both an image and UVs selected.
- Aspect Ratio
Display Aspect for this image. Does not affect rendering.
Draw the image repeated outside of the main view.
Display UV coordinates from 0.0 to 1.0 rather than in pixels.
- Cursor Location
2D cursor location for this view.
- Edge Draw Type
Sets how UV edges are displayed.
Outline, Dash, Black, White
- Draw Faces
Draw faces over the image.
Makes edges appeared anti-aliased.
Show results of modifiers in the UV display.
Shows how much of a difference there is between UV coordinates and 3D coordinates. Blue means low distortion, while Red means high distortion. Choose to display the distortion of Angles or the Area.