surfaces copy problem

I was watching a video to create a mirror, I have implemented the code as it appears in it, but this variable is not copying the corresponding, it only copies the blue area. is this a mistake?

if (instanceCapture != noone)
{
if (surface_exists(surfaceMirror) == false)
{
surfaceMirror = surface_create(captureWidth, captureHeight)
}
surface_copy_part(surfaceMirror, 0, 0, application_surface, instanceCapture.x, instanceCapture.y, captureWidth, captureHeight)...

surfaces copy problem