It obviously was necessary, because some men on this thread, and out there in the real world, thought that a woman knew exactly when her period was going to come. Periods aren't that considerate. Also some men on this thread, and in the world, think she had not bought the right sanitary protection. Sometimes it catches women by surprise and periods can be heavier than we thought. And I'm sure the situation in this photo happens to lots of women. So if it's helped some naïve people understand periods, then it's been useful. And it's helpful to women, if men can be more understanding about what a bloody nuisance periods actually are.