The Harbeth P3ESR speakers are not mirror-imaged, so it shouldn’t matter. Also, it's only on the grills, so you could swap the grills, if you can get them off, (use a magnet).
Being really OCD, I always put mine right on right, left on left
Harbeth P3ESR question (tongue in cheek (I think) but maybe not)
Harbeth P3ESR speakers' fronts are different. One has the "Harbeth" to the left, the other to the right. The back panels are the same.
To owners/auditioners, which way round do you use them? Have you tried both ways? Is there any sonic effect?
I have always run mine with the "Harbeth" to the inside.