RE: how to not show images?

[Drew Adams]

     Is there some way to _not_ show the images in a buffer or in
     all displayed buffers - that is, not to remove them, but to
     simply not display them (perhaps temporarily)?

     I'm looking for a user option (e.g. `show-images-flag') or a
     toggle command (e.g. M-x toggle-image-display).

  maybe `auto-image-file-mode' is what you want?

No, I already checked that out (and the rest of library image-file.el). That
library just provides a minor mode for showing image-files graphically or
visiting them as text/binary files.

What I'm talking about is an option to not show the images that are normally
displayed in a buffer - any image in any buffer. I don't want to visit the
image files to look at their text/binary contents. I want to see nothing (or
perhaps some replacement character sequence or overlay) in place of each
image, and otherwise see the buffer they are inserted in, normally.

Web browsers let you turn off image display - you see a Web page with each
image replaced by a small proxy/placeholder symbol. That's the functionality
I'm talking about.