Hello oosolovely, Very nice.!!! The new console is a much better fit too.. .. See how fantastic that new lamp is with the chair and the pendant... Like the new little bust too, it works nicely with the mirror and the console table.. Gr8 job!! : ))

It looked the same as this but was much more expensive. https://www.amazon.co.uk/YUYUE21-Reusable-Universal-Anti-Slip-Double-sided/dp/B07QDR8HFS/ref=asc_df_B07QDR8HFS/?tag=googshopuk-21&linkCode=df0&hvadid=353673854068&hvpos=1o8&hvnetw=g&hvrand=9510518791344735472&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=1007147&hvtargid=aud-545671390501:pla-779290323582&psc=1 There's some others shown underneath that say they’re stronger.

I use command sticky tapes and hooks for this purpose for my girls. Works well and doesn’t damage the paint. It works better on non Matt paint though. Hope this helps :)

Screws with a 6mm head sound like they’d probably be too small, but it depends on the length and screw size (both of which are independent of the size of the screw head). Into masonry, I’d be going for screws 50mm long, with about a 10mm head on them, as you suggest, and a screw size 8 or preferably 10, with matching rawl plugs. I’d also use round headed rather than countersink screws for a more secure hold. But I’m puzzled by your photo - how is that fitting attached to the mirror? It looks like it’s surrounded by corrugated cardboard!