May have been hard to understand:
The link is over an image, using title tells the bot what the linked page is about.
Code:
<a href="#" title="my phrase"><img src="img.jpg"></a>
An information tag used to tell what the nature of the picture is about. Mostly used for people with vision problems. The title tag will be read back to the visitor so they know what the image is about.
Code:
<a href="#"><img src="img.jpg" title="my phrase"></a>
Tells what the actual viewed picture/thumbnail is about.
Code:
<a href="#"><img src="img.jpg" alt="about picture"></a>
You can use both, use title in your a href's that link to images (not text), and use alt tags in any image with supporting text around it. So not all images need alt tags.