Linked x-position is a strange scale factor

Welcome to the strange world of behind-the-scenes-Motion!

Let me guess, your project size is 3840x2160.

What you see in the UI is not always what is going on underneath. A lot of parameter values are translated for human consumption/interaction.

It looks like you adjusted the Scale value by "hand" and I estimate you're off by 0.0005 — the value should just be 7.68. (It is really hard to visually tell the "absolute" edge of shapes though...)

I figure that the Motion coordinate "playground" is 1000x1000. Coordinate values are adjusted by scale to the size of the project, and if I'm correct in your case, that's 3840x2160.

Your project is 3840 wide. Divided by 1000 = 3.84. Since you're scaling the rectangle in 2 directions at the same time, that's twice the "rate" or 3.84 * 2 = 7.68.

I think you'll find that if you run the exercise in the vertical coordinate space, your scale for the Height of the rectangle should be 4.32.

I made the project you described in 1920x1080. The Rectangle Width needed to be scaled by 3.84 (1.92x2) and the Height by 2.16 (1.08x2).

You will run into these issues when you have to link with parameters that are not the same type of value as in this case Width is not "like" Position.

None of this stuff is documented, so what I just told you is based on how I reason what I've been able to figure out. The 1000x1000 coordinate grid is one of those guesses. You have to "work the numbers" until you see something recognizable, even if the decimal places don't match (like the 3.84 factor - you should be able to recognize it is a factor of 3840... etc...)

HTH