That's a piece of wood to "protect" the floor, like the piece behind the gunner platform. If you look here-
![](../../../svsm.org/albums/HHMWV-M1043/IMGP3981.jpg)
![](../../../svsm.org/albums/HHMWV-M1043/IMGP3982.jpg)
You can see the stowage bracket just to the right of the wood and that the wood is shaped around the bracket. The M1025 has TOW storage, but the 1043 has the M2 stowage bracket. It looks to me like the M1025 either never had the M2 bracket, or it was removed to install the TOW stowage and red switch.