GTrusted

Other than the sleeker size, Sony brought some improvements to the Playstation 4 Slim over the previous PlayStation 4 such as 802.11 a/b/g/n/ac vs 802.11 b/n/g and Bluetooth 4.0 vs Bluetooth 2.1, and lower power consumption.  

However, with the latest firmware 4.0 update that applies to both the Playstation 4 Slim and PlayStation 4 but we believe Sony is the first to enable HDR10 on a HDMI 2.0a interface which doesn't support 4K resolution.  Most people associate HDMI 2.0 with 4K and HDR with 4K, but Sony is actually supporting HDR on the Playstation 4 Slim and PlayStation 4 at only up to 1080p.  To get HDR over 4K, you'll need to get the PlayStation 4 Pro instead.

Sony probably take this unique approach with the Playstation 4 Slim and PlayStation 4 because there isn't enough graphics processing horsepower to support 4K.  Of course, you'd still need to use a 4K TV which supports HDMI 2.0a and HDR10 but while you get HDR, you won't of course get 4K support unless you have the PlayStation 4 Pro.

Sony has deep knowledge of HDMI technology being one of the original founders of the technology so that probably them with the strategy of surprising the world with this non-4K HDMI 2.0a jiu-jitsu to support HDR.  Microsoft had to move to a completely new platform, the Xbox One S, in order to support HDR.  

The benefit to the industry is now there all of a suddenly another 40 million HDR capable HDMI 2.0a which should drive more demand for HDR capable 4K TV's (which not surprisingly Sony also sells).