I realized I haven't done one of my minesweeper threads on this forum yet. Minesweeper is one of my favorite games. It is much more mentally engaging than most people allow it to be. Lots of proof by contradiction in otherwise "guess" situations.
The yellow one has a mine in it because if the one next to it has a mine it means the 2 left MUST have mines to satisfy the 4.
This means the 2 (3 left and 1 up from the yellow) eliminates too many boxes around it for the 4 (4 left and 1 up from the yellow) no longer has enough available boxes around it to satisfy the 4 mine requirement.
In short, if the yellow box DOESNT have a mine in it, the 4 square which is 4 left and 1 up from the yellow box doesn't have enough boxes around it to satisfy the 4 mine requirement because the 2 box next to it eliminates too many boxes.