We illustrate for \$$n=2\$$, which gives the 'little squares' operad.
There is just a single object \$$\square\$$, which serves only as a placeholder.
The entire content of this operad consists of the morphisms from \$$\square_1,...,\square_n \rightarrow \square\$$.
Note: the subscript on \$$\square_i\$$ is only for counting purposes. They're all the same object.