"Sotheby's Concise Encyclopedia of Glass" (eds. David Battie and Simon Cottle, 1997) describe "pate-de-verre" in the glossary as:-
"French, "glass paste". Ancient technique, revived in France during the second half of the 19th century, of melting in a mould ground glass, to which was added a fluxing medium and colouring agent (this was either powdered, coloured glass or metallic oxide)".
As nobody else has commented on this it may well be that I'm completely off the track as far as this piece is concerned! The most famous makers of "pate-de-verre" that I can think of are Gabriel d'Argy Rousseau and Daum, also Henri Cros and Francois-Emile Decorchement are illustrated in this book.
I've seen some modern pieces of "pate-de-verre" and the grains of glass used seen to be much coarser than these turn of the last century artists, so I have seen this technique can produce varying degrees of texture.
Perhaps somebody more knowledgeable can put me right as far as this piece is concerned! Cheers, Sue.