The MacBook AIR has the resolution internally of 2,560 x 1,600 pixels and the Samsung 2,560 x 1 440 pixels .
I guess that if you mirror the screen (have the same image on both) just not. No problem with screen expansion.
Display
Retina Display
13.3" display (33.78 cm diagonal) with LED backlighting and IPS technology, native resolution of 2560 x 1600 pixels at 227 ppi with support for millions of colours.
Supported scaled resolutions:
1680 x 1050
1440 x 900
1024 x 640
400 nits brightness
Wide colour gamut (P3)
True Tone technology