What makes a holiday a holiday? Or, what makes a holiday worthy of a celebratory logo on the world’s most popular website like Google? This question recently prompted me to talk with Michael Lopez, Google’s lead logo designer, to find an answer.September 19, for instance, is Rosh Hashanah. You’ll see synagogues celebrating the Jewish New Year and you’ll hear the “Shana tova!” greeting on the streets of New York. But if Google is true to form, you won’t find it a special Google logo marking the day. In the past, however, you will have found Google celebrations of both the...