Sponge and cubic phase are isotropic phases, while lamellar phase is anisotropic and will refract polarized light. The other difference between sponge and cubic phase is that sponge phase contains more water, and if you obtain crystals, they will tend to be floating on top of the drop. Note that it is possible to obtain crystals in any of the in meso phase. A successful setup will yield a smooth looking drop, just like crystallization in PEG. Non-colored proteins and crystals can be seen as well.
Pictures can be seen here: http://www.qiagen.com/products/nextalcubicphaseproducts.aspx#Tabs=t1