"Rounded" styling simply means that some significant aspect of the house plan has a rounded or curved appearance. This could be the floor plan itself, as with many dome or yurt designs, or it could be just the roof, as with a vault. Other rounded or faceted shapes might have straight sections that combine to create a rounded feeling, such as with an octagonal floor plan.
general, rounded designs impart a rather cozy or embracing feeling to a home.
I have lived for many years in a home composed of a series of domes, where there
are hardly any straight lines. I find that this fits my particular aesthetic
for forms that mirror those often found in nature. These shapes, when combined
with natural materials, create a feeling of your home being an extension of
the natural world around you.