I am a low rated player, I dont even consider myself as a player when I see my blunders (maybe because I play bullet all the time). On the other hand, i stumbled upon this question after another epic failure. I wondered why do I play so directly and my opponent immediately sees my plan and refutes it with a simple response. I googled for “indirect chess” and landed here. No one has answered your question. How come? There are a million players out there and no response for this “indirect chess” question. I wondered why, and figured it out.
I am sure, you know better, good (or at least decent) chess players focus on two things: tactics and strategy. I think "indirect attack" should mean more like "strategy" in this case.
For your example, the g6 square is somewhat weak because of pawn on h6 and you don't have a kings bishop (i.e. LSB), a move like Be5 offering you to play f6 would even more weaken the black king, creating white holes around it and it would more possible for white to attack using his LSB and Queen (again, black doesn't have a light squared bishop but white has).
On the other hand, something immediately visible is the pin that is created on the night on d5. So this is indirect, indeed, but it is strategy (even allowing tactics further).
I would probably play Be5 myself if I was white in this position, but believe it or not, I wouldn't probably do it because I wanted to weaken your light squares and create a pin on your knight and punish you for that, but because I would see the immediate attack on g7 (direct and obvious but easily refuted - the way I play 
).
After getting pushed back by f7, I would realize that "oh I am lucky, NOW I have a target pin to push further, maybe I would be so tempted on the pinned knight and even FORGET that the light squares are weakened and I might have some attack there. Then somewhat if I get refuted by ruining the pin with my bad chess, I would realize that I have an LSB (if I didn't lose it for the useless night), and I can try now a DIRECT attack on h7. Wow, what a bad way of playing chess (should I just quit now, I am thinking of it 
).
When a higher rated player analyses games, and talks about weak squares, triangulations, tempi, and stuff, I say "oh I see, I understand", but all those strategic assessments have value when you can apply them in your games, this mostly differs us from high rated players:
They: 1) Pay attention to their opponents moves, strategic weaknesses of themselves, 2) pay attention to the opponent weaknesses and try to find moves in this order: 1 tactics, 2 strategic moves. They don't classify them as direct and indirect attacks, because there is no such thing as direct and indirect attack (except for my stupid directly refutable moves), but there is tactics and strategy.
i'm not an amazing chess player yet however eventually i want to get a very good rating. therefore i want to know how to spot when your opponent does an indirect attack and even better, how to do one yourself. i had a game at my chess club where my opponent (it was a casual game and my opponent was a lot better than myself.) did an indirect attack which cost me the game.
this is not the exact position but key pieces are definitely noted.
so what'll help me see these indirect attacks. there are probably different ways to do an indirect attack so how can i see these when my opponent plays them and how can i see an opportunity to play them.