In the 1983 adaptation of The Merchant of Venice, why doesn't Portia know Jessica's name?

Question

The 1983 National Theater production of The Merchant of Venice has an interesting take on a moment in act 3 scene 4. According to Shakespeare's script, Portia is giving Lorenzo instructions, and in doing so, mentions Jessica, Lorenzo's wife, twice:

PORTIA:
My people do already know my mind,
And will acknowledge you and Jessica
In place of Lord Bassanio and myself.
And so farewell, till we shall meet again.

LORENZO:
Fair thoughts and happy hours attend on you!

JESSICA:
I wish your ladyship all heart's content.

PORTIA:
I thank you for your wish, and am well pleased
To wish it back on you: fare you well Jessica.

However, in the 1983 adaption, the actress playing Portia adds a small detail that isn't in the script: she forgets Jessica's name twice, pauses, and has to be reminded of Jessica's name by Jessica herself.

Why was that detail added?

Answer 1

Lorenzo and Jessica arrived at Belmont near the end of Act 3, scene 2. It is clear from Gratiano's words that he knows who they are ("But who comes here? Lorenzo and his infidel?"); Bassanio also greets Lorenzo by name, whereas Portia merely says that "They are entirely welcome." (i.e. not you). Jessica speaks exactly seven (contiguous) lines in this scene, namely about Shylock's wish to have Antonio's flesh; due to Portia's follow-up, it is safe to assume that she has heard these words. However, there is no further spoken exchange between Jessica and the other characters in this scene, and nobody mentions her name.

This would justify that in the next scene at Belmont (Act 3, scene 4) Portia has already half-forgotten the name of this very new acquaintance. Without knowing any other details about the production (its director, the main characters, other aspects), it is hard to say whether this lapse of memory has any additional significance.

Note that Wikipedia lists National Theatre productions of The Merchant of Venice in 1970 (directed by Jonathan Miller) and 1999 (directed by Trevor Nunn) but none for 1983. That does not mean that there was no such production in 1983 but only that it may not have been notable enough to be listed, so additional details may also be hard to find. (Or was it a different National Theater/Theatre?)