Shadow over Siberia
This shows the shadow moving south. Any spot directly below the shadow will see a total eclipse when looking at the sun. The outlines of the shadow will be visible away from the sun. The sky within the shadowed area will appear dark. Areas outside of the shadow will remain lit, although with reduced sunlight due to those locations seeing a near total eclipse. From the eclipse site this effect will appear as a circular area of darkness cover some, but not all parts of the sky. The darkness will appear slightly before the sun is completely blocked. The sky will lighten as the edge of the shadow approaches.
The series of pictures tries to capture this effect.