Latias and Latios presented some very unique powers in the movie, such as sight-sharing, invisibility and shapeshifting. Latias commonly shapeshifts to appear the same as Bianca, and befriended Ash under her persona. She may have a crush on him as well, as was hinted in the movie, undoubtedly because he saved her from Annie and Oakley.
+ indicates this Pokémon used this move recently.* - indicates this Pokémon normally can't use this move.
Latias seems to camouflage herself in illusion of Bianca rather than actually transforming.
Latias, even when she camouflage her in human form, can be distinguished from other humans by difference in body temperatures.
Ash was strongly believing that it was Bianca who came to see him off when he leaves Altomare. This was possibly because he had presumably finished his farewell with Latias beforehand. This Latias's ultimate fate is unknown.
The title of the background music during the kiss scene is "Canon", same as Bianca's name in Japanese.
Latias attempting to save Latios from the DMA
Latios and Latias rushing to ward off the tidal wave (in the trailer version)
Latias as Bianca or real Bianca kissing Ash
A picture showing possible ancestors of the sibling saving Alto Mare