You have to manually add your visualization with the name "visu". To do this just double click in the "VC Object Name" column and a display list of your available visualizations should appear. That VNC Viewer is just a Virtual Panel. It can be displayed in your computer when you are connected with the PLC, and need to use the VNC Viewer program on your PC. You should erase that if you are not planning to use it, or if you are, for it to share the same visualization than the PLC in this case, you have to double click the "Master" column and choose the module address DS1.