So think about higher dimensions for a second. If you take a sphere and translate it through 3d space but you an observer can only view a 2d slice with that 2d slice being fixed, then the object will appear as if a tiny circle morphed into a large circle and then slowly morphed back into a tiny circle and eventually disappearing but the object itself was just translating, not actually shrinking.

If you think about a 3d sphere rotating in 3d space but you take a 2d slice where the 2d slice is fixed as we rotate the 3d sphere then you an observer will just see an object that is stationary with no size change of the circle at all.

In other words even if we see an object here in 3d that is fixed size and not morphing that doesn't imply that the object itself isn't moving in higher dimensions. And even if an object is shrinking or growing in our reality that doesn't imply that the object itself is actually shrinking or growing, it could be but we could never know.