It implies that something can be stated or expressed, but it doesn't necessarily mean that it's true or the only thing that can be said.
Here are some examples:
* Es posible decir que el clima es agradable hoy. (It's possible to say that the weather is pleasant today.)
* Es posible decir que ella está cansada. (One can say that she's tired.)
* Es posible decir que el trabajo es difícil. (It's possible to say that the work is difficult.)