Hello, I presume you're asking if the Dell can be used as a Monitor for the Mini?
I doubt it, but does it have Thunderbolt port?
Might try ScreenRecycler...
Replacing "desktop" with "screen" or "display" or "monitor", then probably yes. It depends on which Mini you have (means what graphics outputs you have) and what inputs the screen has.
If both have HDMI, it should be really easy. If the Mac has HDMI and the screen DVI-D or -I, it's also easy, you only need the right cable or adapter. And so on... of course, certain combinations will not work.