Attach image to a form field Adobe Acrobat DC Pro

"it can be the photo attached to the form just for viewing, without having to extract from the form.
Is there a way to do this?"

Yes, use an image field.

Are you intending on extracting that image when the file gets back to you, or do you just want it to be a part of the PDF itself? If the former, there is indeed no easy way of doing it. The best option is to flatten the page the image field is located on, then extract all images from it. It's not ideal, but it works.

There is no easy way to do this.
The images imported into the image fields are not part of the data (FDF or XFDF) of the form, so there is no easy way to retrieve them.

You can use a image field for this.