I have a HUGE monitor so photos are ok for me...
First, go get the latest glcd v3 library s/w from the google code site: (It is currently RC2)http://code.google.com/p/glcd-arduino/downloads/list
The v3 beta code did not have 2560 support.
Then closely look at the included HTML documentation in the library about wiring.
(see the section: Wiring/KS0108 Family - but focus on the diagrams rather than the table)
You have a few wiring errors, one of which might damage the glcd backlight depending on
the glcd module.
All your glcd data and control lines look ok. It is the contrast pot and the backlight
that look incorrect.
If you are sure that your glcd does not need a current limiting resistor for
the backlight then you are ok but,
many GLCDs need a current limiting resistor on the back light.
If yours does and you do not use one, you will soon burn out the backlight.
I can see where there is some confusion about the contrast pot.
The wiring table is a bit unclear about how to wire up the contrast pot.
The wiring diagrams are correct but the table is unclear.
The comment in the table about the VO (contrast out) line is confusing.
The 10-20k pot should be hooked up as follows:
1 leg to VEE
Wiper to VO
1 leg to +5v
(diagrams in the library show ground and that should work but many data sheets actually show using +5v
to one of the legs vs ground)
I'll update the documentation for the next release to be clearer.
Run the diags example sketch to verify everything. If it still isn't working.
Post back with the serial output of the diags.