Yes, from the perspective of the photos we can see that the head of the Kaido does not lose much in width or length (without including the body) in relation to the luffy punch.
But looking at the overall, the kaidou body even though it is not in its entirety of length, even reduced (we can see circular rings) it literally gives the size of about 10 Luffy punches.
Another image if you want to see better. LOL