Layout options -> Results Layout -> Results layout type
There are 4 possible layout types as of now:
Vertical - the results will appear in a horizontal manner, under each other
Horizontal - the results will appear next to each other
Polaroid - the results will appear as a poloaroid stack gallery
Isotopic - the results will appear in a grid style
Instead of changing this option, it is recommended to change the whole search theme under the
Theme Options panel, and choose a theme with the pre-defined layout.