A chamada a cobrar is a telephone call that may be made from any public telephone (known as the orelhão, due to its similarity to big ears) or private line. The collect call is paid by the recipient of the call, and no telephone card is needed. So even, without money for a call, the person can communicate.
If you are lucky, maybe, you'll find some like these... Decorated :)
But, probably you'll see Orelhões like these
These last two are the most common phones that you can find walking in Brazil.