Image-mobject not rotating correctly around in-plane axis

[uwezi]

Description of bug / unexpected behavior

When trying to rotate an Image() around an axis in the XY-plane the image is also rotated around the Z-axis and thus cannot be mirrored.

Expected behavior

When rotating a 2D-object 180° around an axis in the XY-plane it should end up mirrored on the scene.

How to reproduce the issue

A follow up from the discussion on Discord
https://discord.com/channels/581738731934056449/1027662457130455081

Code for reproducing the problem

import requests
import io
from PIL import Image
class TestScene(Scene):
    def construct(self):
        headers = {'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36'}

        response = requests.get("https://raw.githubusercontent.com/ManimCommunity/manim/main/logo/cropped.png", headers=headers)
        image_bytes = io.BytesIO(response.content)
        image = Image.open(image_bytes)

        def reflect_across(self, line, **kwargs):
            A = line.get_start()
            B = line.get_end()
            AB = B - A
            P = self.get_center()
            AP = P - A
            BP = P - B
            perp_to_AB = AP - AB*(np.dot(AP, AB))/(np.linalg.norm(AB)**2)
            
            self.flip(AB).shift(-2*perp_to_AB)
            
            return self
        
        # This binds the defined function reflect_across to the mobject class as if it were a native manim mobject method
        # This isn't necessary but it does allow the function to be used like any established mobject method, such as rotate, shift, etc.
        setattr(Mobject, "reflect_across", reflect_across)
        
        flipflop = ImageMobject(image)
        rect     = SurroundingRectangle(flipflop)
        
        line = Line(3*DL, 2*UP + 2*LEFT)
        
        self.add(flipflop, rect, line)
        
        self.wait()
        self.play(flipflop.animate.reflect_across(line), rect.animate.reflect_across(line), run_time = 3)                
        self.wait()
        self.play(flipflop.animate.reflect_across(line), rect.animate.reflect_across(line), run_time = 3)        
        self.wait()
        self.play(flipflop.animate.reflect_across(line), rect.animate.reflect_across(line), run_time = 3)   

Additional media files

Images/GIFs

see here:
https://discord.com/channels/581738731934056449/1027662457130455081/1028225119857950720

System specifications

System Details

• OS Windows 10
• RAM: enough
• Python 3.9.8
• Manim Community v0.16.0.post0

LaTeX details

• LaTeX distribution (e.g. TeX Live 2020):
• Installed LaTeX packages:

FFMPEG

Output of ffmpeg -version:

ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9.3.1 (GCC) 20200523
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
libavutil      56. 31.100 / 56. 31.100
libavcodec     58. 54.100 / 58. 54.100
libavformat    58. 29.100 / 58. 29.100
libavdevice    58.  8.100 / 58.  8.100
libavfilter     7. 57.100 /  7. 57.100
libswscale      5.  5.100 /  5.  5.100
libswresample   3.  5.100 /  3.  5.100
libpostproc    55.  5.100 / 55.  5.100

[uwezi]

This issue is still open in v0.17.1

TestScene.mp4