Why did Arya shortened her kill list so much in season 6? Or did she lie?

Question

As per this Arya / Hound dialogue , Arya tells the Hound her kill list:
- Walder Frey
- Meryn Trant
- Tywin Lannister
- Melisandre
- Beric Dondarrion
- Thoros of Myr
- Ilyn Payne
- Gregor Clegane
- The Hound
- Cersei Lannister
- Joffrey Baratheon

As per this Arya / Waif dialogue at 2:10 Arya only says:
- Cersei Lannister
- Gregor Clegane
- Walder Frey

waif: "That is a short list. That can't be everyone you want to kill. Are you sure you are not forgetting someone?"
Arya: "Which name would you like a girl to speak?"

Did Arya actually fail this test? Did the waif know Arya was lying about the length of her list and then started testing her by using the second person pronoun, you. And Arya did respond to you. Previously, Arya only talked about herself in the third person.

Or, had Arya's feelings actually changed? Realizing she was too blood thirsty, she had shortened her kill list even before going to Braavos?

And, what did Gregor Clegane ever do to House Stark? Why is he on the shortened kill list? Tywin did order him to raid the Riverlands in season 1, and House Tully is from the Riverlands, and Arya's mother is from House Tully... so is that why Arya hates the Mountain more than even Joffrey? Tywin? (Arya could not know that they are both dead)

Addendum
Unlike her killing of Meryn Trant, I bet Arya now has "permission" to assassinate Cersei, the Mountain, and Walter Frey. After all, she was not whacked for saying those 3 are on the kill list.

Answer 1

No, she didn't shorten it. When outside the House of Black and White at the beginning of season five, she recites four names over and over: Cersei, The Mountain, Meryn Trant, Walder Frey. At the end of season five Arya...

kills Meryn Trant.

...meaning her list of three names in season six was accurate.

Arya knew that Joffrey was dead because she met a criminal called Rorge when travelling with the Hound, this criminal was also in the cage with Jaqen H'ghar when they first met. He was the one that told them that Joffrey was dead. As for Tywin Lannister, I'm not certain, but I think it stands to reason that she overheard it from the Lannister soldiers while she was tailing Meryn Trant.

Melisandre, Beric Dondarrion, Thoros of Myr, and Ilyn Payne were crossed off the list, seemingly because it was just convenient to the plot. We need Melisandre alive, Thoros and Beric are no longer relevant, and the actor of Ilyn Payne took time off from the series during his treatment for and recovery from life-threatening cancer.

Ser Gregor was on the list because he was with the group of soldiers who captured Arya and her friends and took her to Harrenhal.

When the Waif asks Arya if she is forgetting a name, she is talking about Meryn Trant.

Answer 2

The point of the scene isn't that Arya "lies", or that her list is really shorter. It's to signify the point where she realises how the game works, and stops thinking about "Arya's list". She stops naming names, and then offers an open-ended "Which name would you like a girl to speak?".

Jaqen H'gar knows the list during Harrenhaal when he offers the 3 names ("A girl has many names on her lips ....", so presumably some knowledge would have been transferred to the Waif. It's not about Arya lying about the length of her list; it's about "No one" making the switch to stop caring about "Arya"'s list. The waif directs the question "Who do you want to kill?" and Arya's response is "Who do you want me to kill?", not someone that >she< wants to kill. She's evolving beyond Arya's desires, which were what lost her sight in the first place.

Answer 3

Opinionated and a personal take on the question so here goes.

In the entire episode you see Arya "training" she has gotten so good by the end that she fends of her instructor even when blind.

Same with the lies. Every time she lies she get "punished" by the end of the episode she has learned her tells and eliminated them so she has also progressed there.

This part is almost similar to the books, she lies, gets punished, lies more and gets punished. By the end she is so good at lying that her instructor cant tell if she is lying anymore.

Answer 4

Out of universe, the reason the list was cut down was likely because there's little chance that Beric, Thoros, or Ilyn Payne will return to the show in the limited amount of time left, and that Melisandre will not run into Arya again. There's little point in foreshadowing events and characters we'll never see again.

In universe, the best I can guess is that it represents character growth on her part, and that she removed them from her list because she changed her mind like she did with the Hound. The Brotherhood Without Banners trading Gendry to Mel for gold was cruel, but well-intentioned and certainly not worthy of death. Ilyn Payne was a man obeying orders, issued by his king. We never really get an impression in the show that he was a man who relishes in violence (unlike the books). As a hired killer herself now, perhaps she understands his position.

To answer your second question, Arya wants the Mountain dead because he was the one in charge of Harrenhal who ordered his men to kill and torture the captives around her in Season Two.

Answer 5

Another theory that i like a lot, although unlikely, is that the "Arya" we see reciting the list is not Arya but another faceless person in Arya disguise, while the "Waif" training Arya is really Arya evaluating their impersonment of her.