aria-brailleroledescription contains this example:

The following example shows the use of aria-brailleroledescription to indicate that a button's description has a particular braille contraction.

EXAMPLE 18

<button aria-roledescription="planet" aria-brailleroledescription="pln" id="jupiter">
<img alt="jupiter" src="images/jupiter.jpg"/>
</button>

In the previous example, a braille display may display "pln Jupiter" in Braille rather than the verbose "planet Jupiter".

This conflicts authoring advice to avoid using custom role descriptions on interactive elements like buttons... Because users know they can activate a button... They may not know they can activate a "planet." The recommendation is to avoid using this on anything but container roles. Though the button case is not prohibited, we shouldn't use it as the best example.

I'd suggest using an updated version of the "slide" example from aria-roledescription.