simple past or present perfect issue

I would like to ask the reason of using present perfect tense instead of past tense in the italic words in the sentence below:

She has gotten older since we last met her. She also seems to have become funnier.

Is it because the meaning would contain the message that “she had become funnier for a while after we last met her. But she is not funnier than before anymore.” if we use a past tense here?

Thank you.

In a comment wrote John Lawler:

The first sentence uses a resultative present perfect construction to comment on one change that has occurred over a period of time, and it is also used in the second sentence commenting on another change that has occurred during the same time. It's a straightforward parallel construction.