Attacking an Under-defended Kingside

I was taking a break from work, logged onto Chess.com and clicked on the Learn tab under which there are Drills.  In the Drills is one called Attacking and in that is a drill called Squeezing the Tarrasch (not far from the top).  I presumed this was supposed to be a relatively straightforward  attack against an under defended black kingside but after three tries I was not breaking it down.  So I decided to test the Chess.com computer as Black in this position against Stockfish 8 on a multi-processor Macintosh with an Elo rating of about 3200.  Even that monster had difficulty cracking the Chess.com defense but I have to admit it was instructive to watch.  (Ignore the move numbers, they don't correspond correctly to this opening.  The photo is from a recent game in New York's famous Washington Square Park).