If you're not familiar with salted egg yolk, it's pretty much exactly what it says it is. It's often ducks eggs that have been soaked in a brine, only just the yolks and not the whites. This is a really trendy food in parts of Asia, and started its snack life out as a coating on savoury snacks (most famously fish skins). The salted egg yolk however has expanded, and is now not only a popular coating on savoury snacks, but it's also a popular flavour used in sweet treats as well, including donuts and ice cream. Now it appears that they've also found a way to flavour a granola like bar with salted egg yolks as well.
I have to admit, I had very few thoughts on how this particular treat was going to taste, or how the salted egg yolk might fit into the flavour of something that appears to be a granola bar type snack. As it turns out, it really didn't. I can't tell you for sure that I tasted anything salty or eggy about this bar at all. It tasted like a fairly average, slightly bland oat bar. There was nothing particular about the texture or flavour that reminded me of salted egg treats that I've tried in the past. Most shocking is the lack of salt. I would have thought that I was going to be enjoying some kind of creamy sweet treat balanced with a nice salty twist, but that was not the case at all, it was kind of oat like, but mostly sweet.
I'm not saying that this salted egg yolk treat didn't have any salted egg yolk in it, I'm just saying that it certainly didn't feature this very popular flavour. It seems like this bar is designed to sell the idea of salted egg yolks, jump on the bandwagon, rather than actually introduce people to this interesting flavour trend in an interesting way.
If you're interested in trying salted egg yolks for the first time, this is not the way to do it (I'd recommend salted egg potato chips for that). This is just a gimmick to jump onto a trend.