I was out doing some Christmas shopping today. Was in Cost Plus World
Market. They had a stainless steel mortar and pestle; the label says
"made in India" and the little cardboard label inside the mortar said it
was a fixture of Indian cuisine for centuries.

It's not rounded on the bottom; more squared off like a pot. The pestle
is heavy stainless and has a conical end that fits in the square of the
bottom edge.

I did a web search--all the metal mortars I found are rounded, just like
my existing stone one.

Does anyone know about this Indian style and what special uses it would
be used for?

Yes, before anyone asks, I bought it (only $10). Can always use another
kitchen gadget! And I've got a collection of other stainless steel
kitchen tools/toys. But I am curious what I can use it for. I'm assuming
for just about anything I'd use the normal stone one for, but are there
any special uses?