How to display images wrongly classified in keras from my test datagenerator?

I am using image data generator for binary classification. I have built my model and now I want to display images incorrectly classified by my mode.

My code is as follows. I am trying to build an images and labels which are incorrectly classified and then display the images out of 100 from my test generator.

images = []
labels = []
for i in range(100):
    img, label = next(val_generator)
    img = img_to_array(img[i])
    img = np.expand_dims(img, axis=0)
    result = model.predict_classes(img)
    if result != label[i]:
        images.append(img)
        labels.append(label)

I want to display images[]. The code:

images[0]
images[0].reshape(-1)
img0 = array_to_img(images[0])
plt.plot(images[0])

I get the error:

Traceback (most recent call last):

  File "<ipython-input-723-c79b5280f8fc>", line 1, in <module>
    img0 = array_to_img(images[0])

  File "/home/idu/.local/lib/python3.6/site-packages/keras/preprocessing/image.py", line 184, in array_to_img
    return image.array_to_img(x, data_format=data_format, scale=scale, **kwargs)

I think it is about reshaping my images from arrays. How can I display the images wrongly classified? Thank you!

  File "/home/idu/.local/lib/python3.6/site-packages/keras_preprocessing/image/utils.py", line 257, in array_to_img
    'Got array with shape: %s' % (x.shape,))

ValueError: Expected image array to have rank 3 (single image). Got array with shape: (1, 512, 512, 1)