Poppy & Fang - "It's You"

Although I don’t speak Thai, nor am I a huge expert on the Thai music scene, I thought this duet between Thai artists Poppy and Fang is a nice track, with good male/female harmonies and use of strings and keys.

Beyond the song itself, what I found most interesting in this particular version of the video, is that there is a sign language translator helping get the lyrics across to the hard of hearing. I’ve never seen this before for a music video. Is this common in Thailand? Is this on the music video itself or done by the channel? What’s the benefit to using sign language over the subtitled lyrics that also exist on this video (i.e. getting the emotion of the song across)?