My personal preference would be to purchase a longer piece of artwork for above the bedhead and to hang your present art so that you can see it when you are in bed. May I suggest my painting for above the bed. It will show that you have a sense of humour and it will fit your decor. It is called 'There was a young lady who lived in a shoe" and can be seen at Bluethumb https://bluethumb.com.au/lesley-taylor/Artwork/there-was-a-young-lady-who-lived-in-a-shoe-she-had-so-many-children-she-didn-t-know-what-to-do-lesley-taylor and is 152.6cm (W) x 76.3cm (H) x 3.5cm (D)

Looking at the first below I'd say, to be on the safe side, the bedhead should show half to three quarters above your tallest pillow. The second photo I believe shows too much bedhead.

Thanks for your help guys. The builder contacted us today during the installation of the ducted A/C and advised us that we have to drop the ceiling 200m to accomodate the ducts (unless we want a huge bulkhead across the kitchen/living area. SO the gorgeous high ceiling is (unfortunately) no longer an issue. It is really frustrating that they only just figured this out! :-/

Looking at adding something like this onto of the wall. Perhaps increasing the balustrades and incorporating the timber or aluminium slats with a new electric gate. So still has some level of privacy with some plants on the footpath side. Plants an hedges inside the property hopefully to reach the height of the fence in time.