There are a few options here depending on what exactly you are trying to do. In either case, I would recommend taking a look at the following app.
Splunk 6.x Dashboard Examples (https://apps.splunk.com/app/1603/)
(1) Include an html element within your simple xml panel
- refer to the example app for a method to do this
- you can with reference a source html, or embed html directly
- In either case, you can reference an img that exists in your appserver/static directory
(2) For advanced use cases such as embedding images/icons in tables based on cell values
- refer to the examples app for this as well
If you want to embed an image into each row of a table of results, I think the easiest way is to install the latest Sideview Utils app (http://sideviewapps.com/apps/sideview-utils), which is free for internal use, and use its Table module. The Table module is new in the 2.2 version of the app and among other things it has a feature whereby you can embed other modules inside the rendered tablecells. The most commonly used configuration is to embed a Sideview HTML module into the Table, and with some search language to get the correct filenames for each row, you can use this to construct your own
<img> tags whose
src attribute points to one of a set number of images you have put into
There's a page of documentation in Sideview Utils dedicated to this particular feature, although through an oversignt it doesn't actually appear in the navigation. To get to it, navigate to "Module Documentation > Table module > Table - Custom rendering", and then once you're on that page, click the "Next Page" link to go to the "Table - Custom Embedding" page. My apologies about the messed up docs link - I'll fix this in the next release.