Several things come to mind:
(1) As a referee, I would have no idea what D1/GK is thinking or why. The GK's state of mind is irrelevant.
(2) A2 is not offside, A2 is in an offside position, which is not itself a violation.
(3) The only relevant issues are: (a) was A3 onside when the ball was played? and (b) did A2 interfere with the play or an opponent?
As A2 may lawfully be in an offside position, the perception that the GK is focussed on him/her does not create an offside call against A3. The only relevant issue, (3)(b), involves a referee's judgment (and is somewhat a HTBT): did A2 interfere with the GK's ability to play the ball?
A FIFA powerpoint says, in part, that interfering with an opponent "means preventing an opponent from playing or being able to play the ball. For example, by clearly obstructing the GK's line of vision or movement."
You can read it here, slide #17:
https://www.fifa.com/mm/document/afd...e_en_47383.pdf The HS rule and application are the same.