Sun&Moon Kanto arc trailer (presumably from S&M042) vs. respectively EP051, EP134 (and the reanimated scene from BW116, with the wrong-coloured sleeve! Wouldn’t be an Iwane ep without some colouring mistakes, uh~?) and EP273! The last one is obviously the most faithful: for the others, they presented the scenes slightly differently, obviously to allow them to show Kasumi and Takeshi during the Most Iconic Moments (they were present in the originals but not in frame at those exact moments, while Sun&Moon’s new illustrations immediately give us the whole pictures).
The biggest “changes” come with the Yogiras flashback: it’s a mix between the end of EP258 (Kasumi’s pout over the fact that Yogiras only accepts Satoshi’s presence) and the beginning of EP259 (when, in the forest, Satoshi shows off the fact that he’s been Chosen)!
(Also, Takeshi’s jacket consistently has the four pockets in those flashbacks: so it’s not a mistake and he is indeed wearing a new one with only two, in the Sun&Moon episodes.)