Hello,
Do you really need to use Picture control for presenting the data ? The Waveform Chart control available in LabVIEW allows to show your data with bar style. Right click the chart and you can find plot options in Properties window. Please notice, that data points you sent seem to be equally spaced in X-axis, so you don't really need to pass every X value to the chart. They are needed only for proper labeling of axis. The case structure in your code executes only after "for" loop ends. Before it you will not see any results on your plot. Please describe your problem more precisely.
Arkadiusz Roszczewski
National Instruments