Shortly after posting my last message I saw the somewhat contrived relevance of the title, confirming my highlighting choice.
I enjoyed piecing the grid together, but I don't much care for puzzles where completion of the grid is then followed by grid staring and grid manipulation that takes twice as long as the initial fill, especially when one has no idea what one is supposed to be looking for. Nothing in the title, preamble or clears contains anything to steer the solver towards the theme as far as I can see, so it struck me as what has been termed a GWIT puzzle (Guess What I'm thinking), a term that is rather more apt than the any of the six unclued entries.
As if the theme were not elusive enough, solvers were given a preamble that contains a misleading statement (which led me to reject some choices in the early stages that turned out to be right) and some other information that was unhelpful in its presentation.
I shall be interested to see whether Uncle is Angry, Ugly or Happy this week.