The writer maintains that a recently-discovered portrait put up for sale by the Austen family of a teenage girl should be that of well-known novelist Jane Austen and gives some evidence. However, the lecturer refutes it by stating that the evidence in the passage are not at all convincing.
First, as the author claims, that portrait was allowed by Austen's family to use it as an illustration in an edition of her letter as a portrait of the author. On the contrary, the professor says that the edition was published in 1882 when Jane Austen has been dead for 70 years. Therefore, at that time, those family members in Austen's family may haven't seen her in person for once, so their image of Jane Austen must be wrong, and that portrait used in the edition cannot be an evidence.
Second, the writer asserts that that face in the portrait looks like the one in the portiat made by Cassandra, Austen's sister. Nevertheless, the speaker points out that there were many teenagers in the Austens at the time that the paint was made, and the teenagers may look just like Jane Austen since they have some relationship by blood, which means that portrait by Cassandra might be just for one of Jane's relatives with similar age.
Last, in the reading passage, the author suggests that the style of the portrait looks just like that of those works painted by the well-known society portrait at that time, Ozias Humphrey. However, the speaker points out that the canvas of the portrait was sold by a man when Jane Austen was almost 25 years old. Hence, that cannot be the portrait of teenage Jane Austen.