I listen to both the original version of Lullaby For A Princess and the Caleb Hyles cover every day and something I find interesting is how Caleb Hyles's version is slightly more operatic but Christina Ellis is far softer.
Now, I really like Caleb's version because it's a very impressive performance, but the Christina Ellis version hurts more for me because she sounds so gentle and genuinely sad.
To put into words as best I can, Caleb's voice is like the voice of a choir and company: dramatic, deep, and while filled with emotion is separate from the trauma; but Christina Ellis sounds like a sister actually sad about a sister and trying to apologise for what she's done every winter that passes and every morning she sets the moon and puts Luna to bed.