Adicione Dropshadow do MacOS-Sque às imagens
# adds the shadow
convert source.png \( +clone -background black -shadow 100x40+0+16 \) \
+swap -background none -layers merge +repage output.png
# adds the additional space like MacOSX
convert output.png -bordercolor none -border 32 target.png
Zaphod Beeblebrox