Fridge Brilliance: The final time Po sees his mother putting him in the basket, it's CG instead of hand drawn like all the other times we've see it, then it hit me. In both films, the traditionally animated bits were all dreams/fantasy pieces, while the rest of the film, the real story, is CG. The reason why the final time we see this bit in CG is when Po realizes it's not a dream, it's a flashback.
This troper was initially confused by the fact that the prophecy depicted a yin-yang symbol for the "warrior of black and white." Why not outright depict a panda? Why the yin-yang symbol? And then I realized something. Po and Shen are opposites in nearly every way, from fighting style to personality to noble status. Add Po's constant depiction in darker, naturally lit watery environments in contrast to Shen almost always being lit from below by firelight to the mix.
Both Shen and Oogway have had a zooming shot from their eye using a yin-yang symbol, and they are both inventors of powerful weapons. Oogway invented kung-fu while Shen invented the cannon, both utterly destructive if in the wrong hands.
Branching off of that, both were said/used to be able to defeat the other.
The symbolism change from the first movie to the second: The first movie utilized a lot of "Dragon" imagery, which commonly symbolizes the raw power and passions of a person. This can be seen with Po, his geeking out during his training, and his raw talent being able to lead him to victory against the experienced Tai Lung. The movie, too, deals with pain and pride, which are very raw and strong emotions. The second movie, meanwhile, deals with Yin-Yang, which symbolizes true and absolute peace with oneself and their lives. It also clashes with the Dragon imagery of the last movie in Shifu, who was previously tumultuous, emotional, but still powerful, mastering his emotions and attaining the same level of power and mastery as his more peaceful, mellow mentor(Oogway). This clash can also be seen with Po, the "Dragon" Warrior, having harnessed much of his raw talent and emotions by this point to become a formidable and skilled martial artist, on par with Tigress and Shifu despite being relatively inexperienced in comparison. However, in the moments where his peace and focus are disrupted, Po loses his ability to fight thanks to the tumult within his mind blocking his concentration. Furthermore, there's the cannons used by Shen, forged in the shape of a dragon, firing cannonballs that have dragons engraved upon their surface, and are, metaphorically, fueled by Shen's rage, ambition, and pride. He is ultimately defeated by Po attaining complete mastery of his emotions, seen in how he forms the Yin-Yang symbol while preparing to hurl the last cannonball right into Shen's ship. In this, the dragon who attained mastery of his emotions(Po) defeated the dragon who allowed his emotions to control him and drive him(Shen).
Furthermore, it stresses the contrast between Yin and Yang, with Po learning inner peace in water and darkness while Shen is constantly sorrounded by fire and is bright white. In the end, Po ends up staring at Shen under the glow of the rising Sun while Shen is damp because his ship blew up, possibly symbolising inner peace (by elemental harmony) and devastation (by being overwhelmed by an opposing element).
The Soothsayer's prophecy states that Shen will be defeated by a "warrior of black-and-white". When one considers Shen's own coloration and the fact that his downfall was ultimately caused by the very actions he took to prevent it, this takes on a whole new meaning.
This troper was slightly bothered that Po managed to find Inner Peace so young and so fast, whereas Shifu had to go through many years to achieve it. Then I realized it makes perfect sense: Shifu was only confronted with the source of his inner turmoil at an old age, when he finally had to own up to the mistakes he committed with Tai Lung, and accept some of it was his fault and some of it wasn't. Po found inner peace earlier because he had to face his inner turmoil earlier, dealing with his lost family. It is all a matter of facing your issues.
Shen telling Po his parents abandoned him and never loved him may have been partly Shen projecting his own issues regarding his parents.