PySimpleGUIで画像が表示できない

本コードではPySimpleGUIのウィンドウを2回表示させているのですが，一度目(show_candidate)はできても，二度目(show_result)のウィンドウにおいて，PySimpleGUI.PySimpleGUI.Imageのオブジェクトを表示させることができません(show_resultのresult_layoutのbox_imgをコメントアウトすればエラーは吐かれません)．どちらも関数の先頭で画像リストをprintしているのですが，形状的にも問題なさそうに感じているので，困っております．．．

Python
1import numpy as np
2import PySimpleGUI as sg
3import cv2
4import sys
5import io
6from PIL import Image, ImageTk
7from tensorflow.python.keras.models import load_model
8
9
10def get_img_data(f, face_box, maxsize=(120, 120), first=False):
11  """Generate image data using PIL
12  """
13  img = Image.open(f)
14  img = img.crop(face_box)
15  img.thumbnail(maxsize)
16  if first:  # tkinter is inactive the first time
17    bio = io.BytesIO()
18    img.save(bio, format="PNG")
19    del img
20    return bio.getvalue()
21  return ImageTk.PhotoImage(img)
22
23
24def predict(path, face_box):
25  hoge_list = ['hoge', 'fuga', 'piyo', 'foo', 'bar', 'baz', 'toto']
26
27  gray = Image.open(path).convert('L').crop(face_box)
28  img_resize = gray.resize((48, 48))
29  img = np.array(img_resize).reshape(1, 48, 48, 1)
30
31  model = load_model('hoge.h5')
32  pre = model.predict(img).reshape(7)
33  arg = np.argsort(pre)[::-1]
34  pre_result = []
35  for i in range(3):
36    pre_result.append('{}.{}: {}'.format(i + 1, hoge_list[arg[i]], pre[arg[i]]))
37  return pre_result
38
39
40def get_face_position(img_path):
41  face_cascade_path = './hoge/haarcascades/haarcascade_frontalface_default.xml'
42  face_cascade = cv2.CascadeClassifier(face_cascade_path)
43  img = cv2.imread(img_path)
44  img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
45  face_box = face_cascade.detectMultiScale(img_gray)
46  # face_box = face_cascade.detectMultiScale(img_gray, scaleFactor=1.05, minNeighbors=3, minSize=(120, 120))
47  for i in range(face_box.shape[0]):
48    face_box[i][2] += face_box[i][0]
49    face_box[i][3] += face_box[i][1]
50  return face_box
51
52
53def show_result(pre_result, box_img):
54  # result_img = sg.Image(data=get_img_data(path, face_box[index], first=True))
55  box_img = [box_img]
56  print(box_img)
57  result_layout = [[sg.Text('Here are the results.'), sg.Button('OK')],
58                   box_img,
59                   [sg.Text(pre_result[0])],
60                   [sg.Text(pre_result[1])],
61                   [sg.Text(pre_result[2])]]
62# ウィンドウの生成
63  result_window = sg.Window('Result', result_layout, return_keyboard_events=True, use_default_focus=False)
64
65# イベントループ
66  while True:
67    event, values = result_window.read()
68    if event == sg.WIN_CLOSED or event == 'OK':
69      break
70
71  result_window.close()
72
73
74def show_candidate(box_img_list):
75  print(box_img_list)
76  if len(box_img_list) > 1:
77    candidate_layout = [[sg.Text('Please enter a number between 1 and {}.'.format(len(box_img_list))), sg.InputText()],
78                        [sg.Button('OK'), sg.Button('Cancel')],
79                        box_img_list]
80  else:
81    candidate_layout = [[sg.Text('Is this the face?')],
82                        [sg.Button('Yes'), sg.Button('No')],
83                        box_img_list]
84
85  candidate_window = sg.Window('Choose the face', candidate_layout, return_keyboard_events=True, use_default_focus=False)
86  # loop reading the user input and displaying image, filename
87  while True:
88    event, values = candidate_window.read()
89    if event == sg.WIN_CLOSED or event == 'Cancel' or event == 'No':
90      break
91    elif event == 'Yes':
92      index = 1
93      # show_result(box_img_list[0])
94      break
95    elif event == 'OK':
96      print('What you entered：{}'.format(values[0]))
97      index = int(values[0]) - 1
98      # show_result(box_img_list[index])
99      break
100
101  candidate_window.close()
102  return index
103
104
105def main():
106  for img_path in sys.argv:
107    if img_path == 'test.py':
108      continue
109    face_box = get_face_position(img_path)
110    box_img_list = []
111    for i in range(face_box.shape[0]):
112      box_img_list.append(sg.Image(data=get_img_data(img_path, face_box[i], first=True)))
113
114  # print(box_img_list)
115  index = show_candidate(box_img_list)
116  pre = predict(img_path, face_box[index])
117  show_result(pre, box_img_list[index])
118
119
120if __name__ == '__main__':
121  main()

$ python test.py './img/test2.jpg'

[<PySimpleGUI.PySimpleGUI.Image object at 0x7fd4382a4190>, <PySimpleGUI.PySimpleGUI.Image object at 0x7fd429862b20>, <PySimpleGUI.PySimpleGUI.Image object at 0x7fd43834c1c0>, <PySimpleGUI.PySimpleGUI.Image object at 0x7fd418797280>, <PySimpleGUI.PySimpleGUI.Image object at 0x7fd429862d30>, <PySimpleGUI.PySimpleGUI.Image object at 0x7fd43826fd60>]
* Error performing wm_overrideredirect *
What you entered：3
2021-01-09 17:25:51.179516: I tensorflow/core/platform/cpu_feature_guard.cc:142] This TensorFlow binary is optimized with oneAPI Deep Neural Network Library (oneDNN)to use the following CPU instructions in performance-critical operations:  AVX2 AVX512F FMA
To enable them in other operations, rebuild TensorFlow with the appropriate compiler flags.
2021-01-09 17:25:51.192214: I tensorflow/compiler/xla/service/service.cc:168] XLA service 0x7fd3e2ebb0a0 initialized for platform Host (this does not guarantee that XLA will be used). Devices:
2021-01-09 17:25:51.192234: I tensorflow/compiler/xla/service/service.cc:176]   StreamExecutor device (0): Host, Default Version
[<PySimpleGUI.PySimpleGUI.Image object at 0x7fd43834c1c0>]
/Users/hoge/opt/anaconda3/envs/face/lib/python3.8/site-packages/PySimpleGUI/PySimpleGUI.py:7688: UserWarning: *** YOU ARE ATTEMPTING TO RESUSE AN ELEMENT IN YOUR LAYOUT! Once placed in a layout, an element cannot be used in another layout. ***
  warnings.warn('*** YOU ARE ATTEMPTING TO RESUSE AN ELEMENT IN YOUR LAYOUT! Once placed in a layout, an element cannot be used in another layout. ***', UserWarning)

よろしくお願いいたします．