The authors investigate the role of point sources and their power fluxes in the linear sampling method (LSM). They analyze the mechanism of power flux transport throughout the background medium for acoustic waves from both a global and local view point: in the later case, the importance of the flow tubes of the scattered field is highlighted. The authors also extend their previous investigation, both from a numerical and theoretical view point, to the visualization provided by the LSM outside the scatterer. In the appendix, the authors prove a minimum property for cones inscribed in a half sphere.