Symbolism, Imagery, Allegory
Freud's Dream of Uncle Josef is short and sweet, and it doesn't include any elements that he would list as "universal" or "common" symbols. But, as Freud's interpretation of the dream makes clear, its hidden meaning hinges on one crucial symbolic element: a yellow beard.
Let's take a closer look. Here's how Freud tells the dream:
I. … My friend R. was my uncle.—I had a great feeling of affection for him.
II. I saw before me his face, somewhat changed. It was as though it had been drawn out lengthways. A yellow beard that surrounded it stood out especially clearly. (4.1.10-11)
Although the dream seems at first to be about his friend "R.," the yellow beard makes it clear to Freud that the dream has identified "R." with someone else—specifically, his Uncle Josef. Once he makes this connection, Freud is able to interpret the "latent" content of the dream.
In most of Freud's dreams, the symbolic meanings of various dream-elements are specific to his own experiences and associations. Although "yellow beards" don't have universally symbolic meanings in the same way that "long cylindrical objects" (phallic symbols, naturally) do in Freud's thinking, within the context of this particular dream, the yellow beard signals the dream's "condensation" of two very different men.