TUV certification is meritless, and currently means nothing of substance.
They've issued "flicker free" certifications to a number of handsets that evidently flicker.
However with that being said, it's a step in the right direction, and at the very least is it generating further awareness and discussion on the topic of eye strain.
Depending on the quality and type of feedback manufacturers receive from consumers that use these certified devices, manufacturers will undoubtedly try to do more to improve, and hopefully TUV will enforce more thorough and higher stricter standards before granted certification.
Semi interesting side note: 2 previous TCL handsets (from their 20 series) were granted "TUV Rheinland circularly polarized light display" certifications. I didn't even know this type of certification existed. Nevertheless, TCL are using this type of display in some of their upcoming 50 nxtpaper series.