What does the phrase 'to take a good look at yourself' mean?

The phrase \'to take a good look at yourself\' means that before judging someone because you think that they are doing something wrong firstly you should thought: \"Maybe I am not better? Maybe sometimes I do wrong things too, and I should not blame each other for being not perfect?\". Sometimes we forget that we all are human beings, and we all sometime can do mistakes, but it is not a reason to ruin relations. Firstly you should always \"look at yourself\" and understand, that you are a human too.