In confluence, you can simply paste in an image to a text area.
In Jira, on the Mac at least, when you create a ticket, there seems to be no way to paste an image (e.g. from skitch), or even to drag and drop a saved image (simply causes the browser to show that image instead of your ticket).
There seems to be no field to add attachments, and no option to include an image in the description.
Not being able to put screen shots etc. in jira tickets is hugely limiting.
The workaround is to create the ticket, then find it, edit it, then paste in an image to the description.