[jhowell]

When you publish a book on Amazon it will be converted to multiple formats that are each rendered a bit differently. I suggest you keep it simple in order to have the best chance of it looking good on as many devices as possible.

I looked at a book from a major publisher recently with both portrait and landscape images that render well on my Kindle device in either orientation. The code used was:

HTML:
<figure class="IMG-NOS"><img id="fig2" class="img90"
src="../Images/image00123.jpeg" title="description" alt="description"/></figure>

CSS:
figure.IMG-NOS {
	display: block;
	margin-bottom: 0em;
	margin-top: 0em;
	text-indent: 0em;
	margin-right: 0em;
	margin-left: 0em;
	text-align: center;
}

img.img90 {
	width:100%;
}