From RDenallo's comment: "What's in the box?!" is a line from the movie Se7en, as delivered by Brad Pitt. Another component of the joke is that in the movie "Inglourious Basterds," Brad Pitt plays an American Officer in Nazi Germany, who pretends to be Italian. His Italian is terrible and so is his accent.
È means "is". Lui è alto. (He is tall.) C'è means "there is". C'è un libro sul tavolo. (There is a book on the table.) C'è is an elision (contraction) of "ci" and "è" or c'è.
Similarly, sono (3rd person plural) means "are". Albert e Cosimo sono alti. (Albert and Cosimo are tall.) Ci sono means "there are". Ci sono libri sul tavolo. (There are books on the table. There is no elision for ci sono.