Thanks for all your comments everyone.
@ specialbrew
No, actually you're mistaken. Take a look at N902MM on the right hand side and compare it to M-GBAL:
Question for Global Express Pilots
GBAL's trim is set at neutral, whereas 902MM is set to fully negative. As proof, I have a close-up of 2MM's tail:
http://alexpeake.co.uk/bd700/N902MM.jpg
This clearly shows the trim limits marked with red lines and you can see... it's at the fully negative position.
That picture was taken in September where temperatures were at least 20C+ so any theory about de-icing can be ruled out.