Levelling.

I put up a large mirror in the spare bedroom today.  It's a heavy one, probably 25 kilos or so.  It has metal hoops fitted on each side at the back to hang it on the wall.  To accept the hoops, holes have to be very precisely measured out, carefully drilled and plugged and screwed.  All this I did and then, with Naomi's help, we lowered the heavy mirror on.  She stood back to look at it.  "It's slightly low on the right."  I looked for myself and couldn't see it at first, but when I measured the gap up to the picture rail on each side, it was indeed 2.5mm lower on the right.  But the screws are drilled and fixed to the wall and there is no means of adjustment.  Curious as to how I fitted it 2.5mm out, I put the spirit level across the top of the mirror.  Dead level.  Then I put the level on the picture rail above it.  The picture rail is off the level and that is making the mirror look as if it is slightly down on one side.  What to do? Make it look right by trying to align it with the wonky picture rail (not sure how I would even do that) or leave it and remind ourselves, if we ever notice it, that it is the picture rail that is off the level, not the mirror.  In contrast, the daffodils sitting in their vase on the table are askew and random, but then they are meant to be!