Now, here's a video of the best curveball pitcher I know around here. She's a Jr in the same league as my daughter and is committed to Portland State in Oregon ( D-I ).
Is this an optical illusion as well? I sure don't think so. I believe this video should provide another 3-4 pages of debate on the topic.

This girl's ball "appears" to move much more than my daughter's.
She has the same pitching coach as my girl:
Sluggers/FFS -- I am not claiming any amount of break. Heck it could be release point/horizontal pitching angle, etc. I respect your opinion. The fact his -- her rise does not drop as much as her fastball. I know this because, like you probably did in the past, I catch hundreds of them and when I when she throws me 20 rises or so, in the beginning, i tend to catch it up in the top of the web and then when we throw fastballs after that, i catch that thing in the palm for a while until I adjust. Maybe it moves a ball or so, maybe more, but heck a bat is only a few inches wide. It doesn't take much.
As for the curve, yes, it certainly looks better when she steps across her power line and increases the angle from her release point to the destination, but I have zero doubt that this pitch moves horizontally when she throws it right. It skips off the end of my mitt if I'm not paying attention and there is a big difference when she warms up to when the pitch is dialed in. Maybe it moves a ball or 2...I dunno.
The fact is the pitches work and that's the important part. There's a reason these elite pitchers in the CWS throw the pitch...it works.
To everyone else -- thank you for the excellent feedback, as always. I appreciate your eyes analyzing my daughter. It's the little things now that seem to improve her game. She has ambitions of D-I ball. She has a lot of work ahead of her, but she is dedicated. The only problem is her daddy is her club coach ( me ), lol...not to start another debate. ( That happened last time I posted )