"Pickled pig's feet", as served at La Cenaduría La Lupita. They are actually dressed with a light vinegar sauce, and topped with cooked cabbage and carrots, and served atop a crisp tostada de maíz.

Friends on the "Get Stuffed" Branch of the Lonelyplanet.com Thorn Tree http://www.thorntree.lonelypanet.com) inquired as to the drinks in the photo, Another Mexican friend, "Palindroma", replied as follows:
"those drinks in the Patitas de cerdo pic (looking yummy BTW), are tequila (in the round cognac-like cups) and in the shot glasses the green stuff is lime juice and the red stuff is sangrita. Sangrita is a mixture of very spicy and hot tomato juice prepared with salt, pepper, hot sauce, piquín chile, maggy sauce, etc.
When you order a tequila in a bar or restaurant in Mexico, they bring it with a shot of sangrita and a shot of lime juice. The full combo is commonly known as a "banderita" (little flag) because it has the colors of a Mexican flag (green, white and red). If you get just your cup of tequila you can ask the waiter or barman: "con banderita por favor", and then he'll bring the sangrita and lemmon shots.
BTW making a great sangrita is complicated. A good way to judge the quality of a bar, cantina or restaurant in Mexico is by testing the sangrita they serve. Barmans (cantineros) are judged mainly by their sangrita and their martinis. The best sangrita in the world BTW is served at the San Angel Inn restaurant in Mexico City."