This case is similar to the parent/daughter card configuration. The main difference is the ability to off-load the enumeration and configuration responsibility from the parent to the slave in this case. If the slave card is not present Windows 95 will not enumerate it and the drivers won't be installed or loaded for the card. When the slave card is installed it will be detected by one of the Windows 95 enumerators and its drivers will be installed. The responsibility for establishing the communication between the master and slave card will typically lie on the master card.
This poses an interesting problem: the master card may be driven by a default Windows 95 driver which doesn't have the enumeration/communication capabilities for the bus that's connecting the two boards. For example a display adapter with a VESA Media Channel (VMC) on board may work perfectly fine with a generic display driver. But when the slave card is installed the driver for the parent card needs to be replaced with a VMC aware driver so it can communicate with the slave. Currently there is no method to accommodate this scenario unless the display driver is already VMC aware.