In a society where there are so many options and where there are so many ways that people can be influenced, one cannot just blame a condition that is this complex on just one factor. The disease itself is rooted in sociocultural problems, but pre-existing psychological conditions combined with genetics are also at play when discussing the roots of anorexia. Typically, when a person develops this condition, they have at least one or more of the above conditions.
Not that social media standards of beauty are totally irrelevant in the discussion because there is a lot to be said about a society that continues to eschew one body type over others. In fact, when there are no realistic depictions of beauty presented in media, then it is only natural for this distortion to influence the larger populous.
To answer the question, while social media beauty standards are only one part of the sociocultural problems, it can in many ways exacerbate an anorexic’s distortion of what is normal body type.