I can't see the option to do this for a text & image object. Probably this may arrive on future releases of Sense.
For now, a workaround can be to create an extension object that does this.
To do this, go to this url http://localhost:4848/workbencheditor while Qlik Sense Desktop is open. There you can start an extension based on a template. To test the extension, save the changes and refresh Qlik Sense Desktop. Your extension object should appear on the list of objects.
There is a site where the community of Qlik developers is sharing their extension projects. Take a look here:
As for the text & image extension that has conditional formatting, it looks like it's not there yet. Still there are some extensions that you could study in order to build it.
I have verified that this is not something currently available in Sense and is on the road map for discussion. (The ability to place alerting type images, conditions, text etc based on return values from expressions.) As Jose described through the use of Extensions this is definitely possible, but does require some initial effort. However, if you sign up at Branch, (in closed Beta at the moment) - you will be able to take advantage of a growing list of extension objects.
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