Meta: posting images in Diaspora* has caused some confusion, the handling has a not very modern feel to it (think posting images in posts v using images in comments).
Then, there is an image text to be put into two places: upfront, in the square brackets
![enter image description here]
and, optionally, in double quotation marks just before the closing round bracket
(http://foo "enter image title here")
. Screenreaders will display one of them - am not into that, which one is it? The description or title?
The distinction is: Notifications will display the description
. I'm getting emails displaying the image description
in the subject line, even though the post using the image itself and the notification email body do not. So keeping it short is the right way for me, it preserves the context.
The image title
I find more interesting, it containts the text to be shown on
- let your mouse pointer rest over the image, and the browser will display the title. Naturally, readers of i.e. the xkcd comics will know that without saying. I tend to misuse the title
field this way.
Bottom line: use both fields, fill them with appropriate text (short, but not the same), so you know which shows where.