I am trying to connect to my VNC server that i have setup in my ubuntu 16.04 i have tried the default out of the box vnc server Desktop-Sharing i have tried x11vnc. When i connect the connection works fine but after connection this happens

here i connect through localhost using vncviewer from RealVNC

here i connect through the windows 7 os that is running on virtualbox in bridged networking mode i am using Vncviewer from RealVnc to connect to the vnc server

i am using this command to run x11vnc

sudo x11vnc -auth guess -forever -loop -noxdamage -repeat -rfbauth /home/shady/.vnc/passwd -rfbport 5900 -shared

what is happening ? and how to avoid this