animating_gif_in_pythonista_scene

# coding: utf-8
import scene
import ui
from PIL import Image as PILImage

class MyScene (scene.Scene):
    def setup(self):
        self.im = PILImage.open('tunnelswirl.gif')
        self.mypalette = self.im.getpalette()
        self.savefile = 'tmp.png'
        self.toggle_state = False
        self.sprite = scene.SpriteNode(scene.Texture(ui.Image.named('Snake')),
            position=self.size/2,
            parent=self)
                     
    def update(self):
        if self.toggle_state:
            try:
                self.im.putpalette(self.mypalette)
                new_im = PILImage.new("RGBA", self.im.size)
                new_im.paste(self.im)
                new_im.save(self.savefile)
                self.sprite.texture = scene.Texture(ui.Image.named(self.savefile))
                self.im.seek(self.im.tell()+1) 
            except EOFError:
                self.im.seek(0)
                #self.im.close()
                #self.im = PILImage.open('tunnelswirl.gif')
                #self.mypalette = self.im.getpalette()

    def touch_began(self, touch):
        self.toggle_state = not self.toggle_state
        if not self.toggle_state:
            self.sprite.texture = scene.Texture(ui.Image.named('Snake'))
            
scene.run(MyScene(), show_fps=True)

use seek(0) instead of opening and closing again as suggested by @ccc