I can see the grey area to the right of the category name allows for up to 3 lines of text from the category description admin. This actually looks fine as long as you remain within the 3 line limit as it centres the text (can be just one line or two lines) to the right of the category name.
Adding an image screws the layout at the moment so it’s going to need a new CSS style to move the image so its under the text (might look good if its semi transparent). I think that would work as a way to identify categories with graphics as well as or instead of text. So you could use text in the graphic itself instead of in the description.
You can see an example of the header correctly described with text here: