It does show that his view is blocked. It’s a rare case but is still correct in law IMK
No it's not - the law does not say that an offside offence is committed if all that happens is that an opponent's view of the ball is blocked. In terms of interfering with an opponent, the law says it's only an offence if the player is "
preventing an opponent from playing or being able to play the ball by clearly obstructing the opponent’s line of vision."
Even if Kane was clearly blocking the opponent's line of sight (which in itself is somewhat debatable) he did not prevent him from playing the ball. You'll also note that it doesn't say prevented from
attempting to play the ball, it says prevented from "playing or being able to play the ball." The defender was on one post, the shot from just outside the 6 yard area went in at the opposite post. No matter what Kane did, that defender never had a chance of playing or being able to play the ball.
Also, as
@JH says, the defender was moving away from the ball - the screenshot below shows he has moved even further away from the ball by the time it hits the back of the net, than he was in the screenshot you posted.
It was the player's distance from the ball and his movement relative to it that prevented him from playing the ball, not anything that Kane did.