An image of Mexican agua fresca sellers published today by Rachel Lauden reminds me of this:
From: Los Mexicanos pintados por si mismos, por varios autores. Edicion de m. Murguia. published by Casa de m. Murguia portal del Aguila de oro. Mexico. 290p. originally issued in parts 1854-1855.
Thanks to ethnobotanist Dr. Joe Cahill, who provided me with this image.
I'm not entirely sure how to interpret it. She is selling the beverage in the large jug, but I'm not sure why she has both bowls and drinking glasses.