What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Thank you for contacting us. Unfortunately image attachments to matrix is not yet possible I will submit a feature request about this so it can be added in the future release. You will get notified via this thread once this feature have been implemented. I guess if you customize the code using your form source you can insert a section for your image but you have to embed your form using a form source code.
With regards to adding form to joomla you can use these guides on how to http://www.jotform.com/help/keyword_search.php?rpp=0&search=joomla.