It does @gabrieljim , the object origin will also move to the centre of the world.
On that subject, applying the location, and rotation, is something you do very rarely, whereas applying the scale is something you don’t do rarely.
Your problem came about because you were not modelling at the centre of the world.
Remember your origin needs to be at the point where you would place a real mirror. In the image you shared, you could of put the origin at the vert on the tip of the nose.
