By default, Displayr compares each month to the previous month. This is done by setting Date/Time/Wave to Compare to the previous period in the advanced Statistical Assumptions settings. See How to Conduct Significance Tests by Comparing to Previous Time Periods
This is illustrated in the table below.
You can also tell Displayr to compare the data to all the other time periods (see Testing the Complement of a Cell). For example, the prominent red arrow for September 2012 indicates that the NPS for that month is below the overall average.