Final answer:
Inside a Mexican restaurant, common decorations include piñatas, sombreros, maracas, and cacti, which all contribute to an authentic Mexican cultural atmosphere.
Step-by-step explanation:
A decoration you might find inside a Mexican restaurant is a piñata. Piñatas are colorful paper-mâché creations often filled with candy or small toys, which are traditionally broken during celebrations. Other typical decorations include sombreros (wide-brimmed hats), maracas (hand-held musical instruments), and cacti which reflect the cultural heritage and festive spirit of Mexico. Decorative elements such as these contribute to the authentic atmosphere that diners experience, evoking the rich Mexican culture and traditions.