In the episode, Arya spots Brienne training Podrick in sword fighting technique in the courtyard at Winterfell, and decides to challenge Brienne herself. At first it seems unlikely that tiny Arya will have any chance against towering Brienne and her powerful sword-strokes, but as we've learned again-and-again, it's never wise to underestimate Arya. In the sequence, the young Stark woman shows off all the moves she's learned over the years from all her instructors, including the late lamented Syrio Forel and the still-living (and now beyond-the-wall-bound) The Hound - who was himself once beaten by Brienne - finally besting Brienne by whipping out the dagger given to her by Bran after he got it from Littlefinger.
YouTube user Omid G posted the above mash-up video that adds a Star Wars spin to Game of Thrones by putting lightsabers in the hands of Arya Stark and her sister Sansa's one-time protector Brienne of Tarth. Podrick also gets into the action, getting his own lightsaber (but of course he doesn't last long against Brienne). Note that Brienne gets a blue Obi-Wan Kenobi lightsaber, while Podrick sports the green version used by Luke Skywalker in Return of the Jedi. We can't help but note that Brienne of Tarth actress Gwendoline Christie already has plenty of experience with the tech of the Star Wars universe through her role as Captain Phasma in Star Wars: The Force Awakens and the upcoming Star Wars: The Last Jedi.
For fun, Arya gets a purple lightsaber of the type previously used only by Mace Windu, Samuel L. Jackson's character in the prequels. Considering the diminutive size of Arya's sword "Needle," perhaps it would have been more appropriate to give her a tiny green Yoda-sized lightsaber instead. Her dagger remains an old-fashioned Valyrian steel model and not an updated Star Wars dagger.
On GoT, the Arya vs. Brienne fight served the purpose of showing us just how far Arya has come in her training while also signaling a possible future alliance between the two very formidable characters. With things about to get serious in Winterfell thanks to Jon Snow being absent and Littlefinger doing his usual scheming, it would be good for Arya to gather some friends around her. Tough as she might be, she could find herself in over her head as things get even more dramatic for her and the other Stark kids in the last handful of Game of Thrones episodes.
Source: Omid G