That the effect is not different from the cause is shown here. In Sutra 13, the Sutrakara spoke from the point of view of Parinamavada and refuted the objection raised by the opponent that Brahman cannot be the material cause as it contradicts perception. In Parinamavada, Brahman actually undergoes transformation or modification. Now the same objection is overthrown from the view point of Vivartavada. In Vivartavada there is only apparent modification.
Rope appears as a snake.
It is not transformed into an actual snake. This is the doctrine of Advaita of Sri Sankara. In the previous Sutra the simile of the ocean and the waves was stated, accepting the apparent variety of objects. But in reality, cause and effect are one even now. Name is only a verbal modification.