The on-boards I've seen look the same, so I can't see any obvious difference other than the fact that Blancpain seem to use the National pit straight as their start/finish line rather than the International straight.
One slightly curious thing I've noticed is that at the start of the Blancpain coverage they said the track was 5.901km and that appears to be the length of the circuit used in AC, however, on the Silverstone website lists it as 5.89km. On Wikipedia the F1 fastest laps are listed as:
Arena GP Circuit (2011-Present)
Length - 5.891km
Turns - 18
1:30.621 (Lewis Hamilton, 2017)
Arena GP Circuit (2010)
Length - 5.901km
Turns - 18
1:30.874 (Fernando Alonso, 2010)
As far as I know the only difference between 2010 and 2011 is that they were still using the National pits in 2010 and then from 2011 onwards they started using the International pits. I'm not sure how that accounts for 10m of circuit length vanishing, perhaps someone at Silverstone just bought a more accurate trundle wheel
I really like this image of the Silverstone track layouts over the years. I always liked the late 90's layout with the Bridge/Abbey section. It's a pity it's no longer used!
Finally, some on-boards from 2010 using the National pits (and you can see the International pits still under construction), and 2011 with the International pits now in use.