Each row containing a multi-part geometry will be split into multiple rows with single geometries, thereby increasing the vertical size of the GeoDataFrame.
The first row is a multipolygon with three parts.
import geopandas as gpd
df = gpd.read_file(r"C:\GIS\GIStest\multipolygons.shp")
df.plot(column="id", cmap="cool")
#df.head()
# id geometry
# 0 1 MULTIPOLYGON (((633399.839 7186225.194, 635561...
# 1 2 POLYGON ((640064.755 7186290.697, 640064.755 7...
# 2 3 POLYGON ((638721.946 7182507.908, 638721.946 7...
# 3 4 POLYGON ((633989.365 7187502.500, 633989.365 7...
exploded = df.explode()
# exploded.head()
# id geometry
# 0 0 1 POLYGON ((633399.839 7186225.194, 635561.434 7...
# 1 1 POLYGON ((636069.081 7186143.316, 637280.883 7...
# 2 1 POLYGON ((636232.838 7184571.247, 637575.646 7...
# 1 0 2 POLYGON ((640064.755 7186290.697, 640064.755 7...
# 2 0 3 POLYGON ((638721.946 7182507.908, 638721.946 7...