How can I view the full image of an image in a Google Doc? (e.g., hover over image to get a popup with the whole full-sized image)
You will see the original image size within the cell if you display it at that size. Here is tips a pic in a cell, plus a 3/4 size view of it (preview)
The first instructs you to resize the picture inside the cell, maintaining its aspect ratio. 2. Extends or compresses the image so that it fits within the cell. Leaving the image at original size results in cropping. 4 provides the ability to specify a customized size. This mode prevents the cell from resizing to fit the image.