Cloning Laptop display to 2nd laptop

Is there a way to clone one laptops display to a 2nd laptop without the use of an additional software, such as LapLink? My boss has a 12.1″ touchscreen laptop and wants to use a 2nd laptop as a 2nd display screen which will clone the smaller touchscreen. (For portability purposes, he does Not want to use a stand alone monitor for this purpose. Thus, my dilema.)

I haven’t been able to find a portable monitor and if someone would just make one in the style of a laptop,that would be clever.

I was trying to use Remote Desktop through a crossover cable, but I am unable to clone one laptop’s display to the other.