OK after exhaustive tests:
Device 1 - Motorola Moto G - Sreen Size: 4.5", Resolution: 720 x 1280 pixels, Pixel Density: 326 ppi, Screen Type: IPS LCD
Can see the curtain a little bit.
Device 2 - Nexus 7 - Screen Size: 7", Resolution: 1920 x 1200 pixels, Pixel Density: 323 ppi, Screen Type: LED-backlit IPS LCD
Can see the curtain.
Device 3 - Desktop PC:
Monitor 1: iiyama Prolite E2473HDS - Screen Size: 23.6", Resolution: 1920 x 1080 pixels, Pixel Density: Dont Know, Screen Type: LED-Backlit TN LCD
Can see the curtain the best on this one
Monitor 2: Dell UltraSharp U2412M - Screen Size: 24", Resolution: 1920 x 1200 pixels, Pixel Density: Dont Know, Screen Type: LED-Backlit e-IPS
Cant see the curtain
I have had a look at the contrast and brightness specs between the 2 desktop screens and the iiyama screen has a 5 000 000 : 1 dynamic contrast ratio where the Dell is 2,000,000:1 so that is probably why I can see it on the iiyama better than the Dell. But the Dell is an IPS Panel where the iiyama is only a TN Panel and the
blacks on the Dell are very very very black indeed.
I can see the curtain a bit on the laptop which is a Sony i5 with a 17" LED lit screen but I can find any other specs for it.
Conclusion: I can see the curtain on some devices better than others