Hello Shabu,
The constant you see on that diagram can be obtained from the Numeric >> Additional Numeric Constants subpalette...it is called a "Listbox Symbol Ring Constant". To use your own images, you could create a custom control of a picture ring and then use this as a constant on your block diagram. You can read the on-line help in LabVIEW for more information about custom controls.
Please let me know if you have any other questions. Good luck, and have a nice day.
Darren