Target Display Mode can be used.
iMac 27" 2009 and 2010 can be connected to the BizonBOX via DisplayPort to Mini DisplayPort adapter.
iMac 2011-2014 can be connected to the MacBook and using an iMac in this mode will not allow for accelerated graphics options. There are exceptions when using certain applications. More details »
iMac 2015 does not support Target Display Mode.