You can do this in one of two ways: by adding code to BoggleGUI or by calling the appropriate code in the GUI when finding words from your AutoPlayer.
for(String s : setOfWordsFound){ computerArea.showWord(s,myModel.cellsForWord(s),computerPlayer); }
myView.showWord(s,list,this);
In that code the this is the IAutoPlayer and the list is a list of board-cells built up as each word is found.