5. ImageSequence all_frames

See: https://pillow.readthedocs.io/en/stable/reference/ImageSequence.html#PIL.ImageSequence.all_frames

5.1. All_frames

Use the ImageSequence.all_frames(im, func=None) method to return a list of images from applying a given function to all frames in an image or a list of images. The frames are returned as a list of separate images.
im - An image, or a list of images.
func - The function to apply to all of the image frames.

5.2. All_frames

The code below modifies all frames and saves them.
from PIL import Image, ImageSequence


def addOverlay(frame):
    im = Image.open('images/ambulance_L.jpg')
    position = 'bottomRight'
    coords = {
        'topLeft': (0, 0),
        'bottomRight': (frame.width - im.width, frame.height - im.height)
    }
    frame.paste(im, coords[position])
    return frame

with Image.open("gifs/transform_tilt_x.gif") as im_gif:
    # Run 'addOverlay' on each frame in the image
    frames = ImageSequence.all_frames(im_gif, addOverlay)
    # Save the frames as a new image
    frames[0].save('gifs/transform_tilt_x_overlay.gif', save_all=True, append_images=frames[1:])
../_images/transform_tilt_x_overlay.gif