The text on the right, under the poster is ShortDescriptionLine1 and ShortDescriptionLine2. The text on the button is Title.
If you specify a ListItemHighlightHD/SD graphic via the theme, the available text width for the button will adjust to the width of the provided graphic. You'll get odd results if you do supply a poster, but if you're not, then it should work the way you're wanting.
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