I didn't even think to ask the question myself, I just assumed these were video's! Very cool that they are now integrated with DOFLinx, here is the detail from the Readme.txt that is part of the file:
DOFLinx and Pinball FX2 Backglasses
This is a quick checklist for installing a directb2s file with PinballX2 using DOFLinx.
For full details please take the time to read the DOFLinx guide.
For support go to the DOFLinx forum at www.vpforums.org
1. Decide where you want the FX2 B2S (directb2s) files to live. I made mine a sub-directory of my DirectOuput, so I'll refer to that as C:\DirectOutput\DOFLinx_FX2_B2S\ - for you its your choice
2. Unzip your directb2s file to that folder
3. Ensure you have at least V5 of DOFLinx installed
4. Make sure you have the latest FX2 files installed
5. Edit your DOFLinx.INI file, two things to add
a) PATH_FX2_B2S=C:\DirectOutput\DOFLinx_FX2_B2S\
b) PATH_B2S_SERVER=C:\VP\Tables\ (Where ever on your system you have B2SServerExe.exe)
6. From within PinballFX2 turn off the cabinet setting for 'Relocate Backglass', you should leave the DMD relocated. (If you don't do this FX2 will place its image over the B2S backglass)
7. Enjoy