I am quite new to Pianoteq, piano and playing music, I learn playing on my digital piano (FP-10). Currently, I want to play this, you know it for sure.
https://youtu.be/SjVO2t8BH9w?si=GT5cvkl38jT8DodQ
Together We Will Live Forever — Clint Mansell

And I have stumbled over a fundamental question for me - Can I differentiate grand piano from upright piano? Because the more I listen to the above track, the more I feel it's upright piano, or something mixed. I have buying U4 in mind because, IMHO, it sounds like the (upright)piano in that track in the C5 region and above. It's so close to black friday, I don't know if I can hold it…

So, my question is:
Can you always say 'it's grand' / 'it's upright' when you listen to the music? What to look for when trying to differentiate those two guys?