This is certainly one interpretation!  

After happily and excitedly telling her grandmother that she is ready to take the mighty big step of going downtown to the desegregated Nashville Public Library by herself on the bus, 'Tricia Ann is not happy about sitting in the back of the bus in the "Colored Section".  She is staring back with a look of guarded irritation as if she is saying to the reader. "See what I have to live with in my world?"  She may also be looking back someone who has made a remark to her as she got on the bus. 'Tricia Ann's eyes are the only ones we see clearly so we focus on her point of view and opinion about the Jim Crow laws governing bus seating.

 

  Would you like to consider another interpretation?