In unit testing a tester should cover the functionality of 
the application, look and feel of GUI should be applied 
correctly. You can check the contents of GUI aswell 
alignment of text, grammer of text on screen, etc etc

unit testing: test the code snippets,loops,braches,syntaxes.

Testing of Code that pertains to the design doc which 
covers the correspoinding snippet. In Unint testing the 
tester will perform:

Statement coverage.
Decision coverage (Or braching coverage).
Boundry anlysis.

Mainly the code coverage which involves multiple reviews of 
the code prior to the UT.

Correct me if am worng.