Use python PIL If you play around with different operation for each pail of pixels you’ll notice that a lot of them turn white when using xor. Make the non white ones obvious.

Code:

from PIL import Image

image1 = Image.open("scrambled1.png")
image2 = Image.open("scrambled2.png")
output = Image.new("RGB", size=image1.size)

data = []

for pixel1, pixel2 in zip(image1.getdata(), image2.getdata()):
    data.append((pixel1[0] ^ pixel2[0], pixel1[1] ^ pixel2[1], pixel1[2] ^ pixel2[2]))
    if data[-1] != (255, 255, 255):
        data[-1] = (0, 0, 0)

output.putdata(data)

output.save("output.png")

Final flag: picoCTF{2a4d45c7}