I saw a video demonstrating the SU-30's thrust vectoring nozzles and noticed that the horizontal stabilizers begin moving up/down before the nozzles do. It seems that the F-22 also has this delay.
Then, after it's in an upright/downright position, if the pilot brings the stick back to center, both the nozzles and the stabilizers move at the same time. This leads me to believe that this is probably not some mechanical lag that causes it. So, why is there that initial delay?
Photo demonstrating this delay (note how the nozzles only begin moving some milliseconds after the stabilizer starts moving):