If he had been a kinder person, Sephiroth may have gone further after having noticed the way she was observing. It was clear to him that she wasn't too sure now what to do with the weight she had selected. But he wasn't the one to be showing anyone how to better themselves. What even was she doing in this part of the gymnasium if she wasn't familiar?

He was happy enough to allow her to watch him, and to take what demonstration she could that way but at the end of the day all of his own skills and perfections have been attained largely by his own pursuance of excellence. So it should be the same for everyone else if they wished to even scrape anywhere near to his level.

Sephiroth would even flick the mass of silver hair off his shoulder so that she could see better how the muscles move, after all it satisfies his ego well enough to show off.