Is this Colin seeing Pen dancing with Debling and him starting to feel yearning and desire for her as more than just his friend? He sees them dancing, reminds himself that she’s wanting to find suitors, but something in him is nagging that it isn’t quite right and something is off about, whether it be Debling or his feelings… hence his watery eyes and look of almost resignation
i've never watched the rah concert but i've seen clips and the way sierra acted especially in motn and the final lair was very different of the way she acted in other productions, she was way into him. did she choose to play that way or the director told her to
Well, I certainly think it can be both; Sierra Boggess wanting to play it that way and the director wanting it a certain way, are not mutually exclusive. For all we know, they were in total agreement as to how Christine should be interpreted in the concert.
That being said, I do understand what you're saying: that Sierra Boggess acts differently enough in the RAH concert compared to her Las Vegas and Broadway runs that it seems like something was different. So yes, it is very possible that the Laurence Connor's direction in the RAH concert pushed her to be more receptive towards the Phantom, and some have theorized that he was trying to make the show line up better with Love Never Dies, which had only just opened in London about a year ago.
However, from what I've heard, Connor apparently denied LND being an influence on his direction, but I do think it's likely that it had an influence on Sierra Boggess and Ramin Karimloo, who were only just in the show some months ago. It's a good possibility that, with LND still so present in their minds, the two played the Phantom and Christine in a way that leans closer to that show, whereas by the time Boggess was on Broadway (in early 2013 for its 25th anniversary and mid-2014 when Norm Lewis joined the show), enough time had passed that LND was no longer such a strong influence on her.
That also brings up another related factor: Ramin Karimloo and Sierra Boggess's famous chemistry with one another. Sometimes, certain actors just click better with each other, and that's the case with Karimloo and Boggess; it's a strong possibility that Sierra Boggess is just more responsive to Ramin Karimloo, and that came out in the concert. I will say that I personally don't think Hugh Panaro and Sierra Boggess's interpretations worked very well, and coupled with her only having a six-week run, it could very well have caused her Christine to seem more standoffish and fearful of Panaro's Phantom. And on the opposite end, Sierra Boggess already knew Norm Lewis from The Little Mermaid and that might have contributed to her being a bit more receptive towards his Phantom, though still not as much as with Ramin Karimloo.
And the last possibility is in regards to the direction, but in another way: that the Broadway direction pushed Boggess to be a little more afraid and less attracted to the Phantom. At least to me, I find that the London direction is a little more experimental and willing to let actors try new things, while the Broadway direction is more consistent and traditional, and that might very well have applied to the RAH concert and Sierra Boggess's time on Broadway, respectively.
Or it could have been a combination of all of those factors. Or some. That's just the nature of creativity and collaboration.