Tea leaf readings can be interpreted in a number of different ways and each way differs from person to person and between cultures.
Usually psychics, mystics, spiritualists and advisers will either do a literal interpretation, meaning whatever symbols appear to you in the brew are obvious and are exactly as they appear, or the shapes that appear can be symbolic and indicative of something else more complex.

Someone seeing an airplane shape in their brew might be seeking advice on an upcoming business trip, or that same shape may be a symbol for travel and excitement waiting to be had.

The image of a book swirling around in your tea may represent the search for deeper knowledge, a fish may mean the pursuit of spiritual knowledge, a mountain may represent a challenge to surpass or a bird may be the harbinger of good fortune soon to come.

Conversely, images that are directly contradictory to what’s happening in the subjects’ life may imply conflict in the person’s thinking. That plane may signify your unwillingness to travel or experience change.

Also to consider, the size of the symbol may indicate the importance of the subject in the person’s life.
Sometimes the positioning of the leaves in the cup can be another barometer for what the future holds, but the top or the rim of the cup almost always represents things that are happening or may be happening in the near future.

All attempts at interpretation are subject to the expertise and scrutiny of a psychic or spiritual professional.