I was very confused by the rule 2 before I read the solutions. Then I realized that the rule 2 means:
"For all rows that have a black pixel at column C, they should be exactly the same as the row R in terms of looking"
So in the example, row 1 looks exactly the same as the row 0, but row 3 looks not the same as row 0.
I got confused by thinking row 1 and row 0 being the same means that the number of black pixels they have are the same or all other possibilities. Maybe that's because English is not my native language.