Images are almost identical to links, but an image starts with an exclamation point !.
Alternate (alt) text is displayed when the image can't be shown, or for the visually impaired.
It's fine to leave this blank but the [] is required.
You can also use complete URLs, such as
http://a.com/dog.jpg
Make sure there are no spaces between the brackets.
CloseDefinition identifiers may consist of letters, numbers, spaces, and punctuation. They are not case sensitive.
The link definition can be placed anywhere after a blank line, but is generally near the bottom.
CloseThe title of the image is optional.
A title provides more textual detail about what the image shows or contains.
CloseMake this image appear – no need for alt text or title, leave those blank: