Shelia is unhappy when she looks in the mirror. For as long as she can remember, she
has been uncomfortable with her appearance. However, Shelia is constantly calling
her younger sister ugly. According to Freud, Shelia may be dealing with the anxiety
caused by her feelings about herself by using the defense mechanism of:
sublimation
displacement
repression
projection
reaction formation

According to Freud, Shelia may be using the defense mechanism of projection.

Explanation:

The projection mechanism is when a person takes the attributes in themselves that they dislike/hate and projects it onto another person. This can cause hurtful things being said to someone, in this case the sister. By using the features someone dislikes on themselves they use false accusations towards others.

When someone is using the projection mechanism they are repressing their own feelings. They are unable to handle their own flaws. Some of the things that can be projected to others are;