- plot.png only has data for one test run
It appears from comments in scripts/parser/common.py that there used to be a command line argument (to parser.py) that controlled the number of test runs to include in the plot.
See Dhrystone.Dhrystones for an example.
Also, plot.png is not interactive (like the flot plugin is).
Also, plot.png only shows the data point for one metric.