Total P/L
Assuming a year-to-date analysis, which is the period from the beginning of the year to the previous day's end-of-day. Then Total P/L measures the previous day's Account Value less the Account Value at the beginning of the year, and less any cash and security transfers during the period.
Cumulative P/L
An analysis of year-to-date Cumulative P/L would show the end-of-day Position P/L (changes resulting from security-related activities) for each day within that period. The figures depicted in the graph would correspond to the Position P/L shown in the Account Value summary, for each day within the given analysis period.