Paul was still the same approximate height as John three months later, during the filming of the Day Tripper video on November 23rd 1965; it's hard to capture on their exact heights in a frame like this, as they bop around a lot while performing, but they appear roughly the same height: 
 

              
  
     From the other photos in the booklet, they all seem to be wearing the same kind of costume shoes to match their outfits, and they actually rented these costumes from a costume shop, so it is unlikely that different heels are to blame 
     Now, when we view the wax figures of the Beatles in the same photo, Paul's figure appears the same height as John and George. Madame Tussaud's is known for preparing their figures to the subjects specific physical measurements, and indeed they have prepared John, Paul and George at aprroximately the same height: 

     We see this difference in height again in the film Magial Mystery Tour. Here we see the boys standing side by side, again wearing matching shoes; "Paul" is on the right end and clearly stands a few inches taller than John and George. His shoulders in particular are considerably higher. You can also just make out the infamous "black carnation" clue; the others wear red carnations, while "Paul" is singled out by wearing a black carnation: 

     And here we see a frame from "I Am The Walrus"; note that he is actually wearing no shoes in this video sequence, and yet he still appears taller than the others. Could this man really be the same height as John Lennon and George Harrison? 

     So let's come back to the comparison from the introduction page: 

     Although the angles are a little different, I think with the other evidence and the fact that the head size is the same result as the head size comparison make this comparison at least partly reliable. Again, the bass is the same model, a Hofner 500/1, and the headstock, neck length and fret spacing has been equalized close enough to say that these pictures are now on the same scale. 
     Paul, John's and Georges heights are was listed as 5'11" in biographical descriptions going back to 1963, and Paul  was definately the same approximate height as John Lennon at the end of 1965. He was 23 going on 24. Men generally stop growing in height between the ages of 17 and 21. It is very rare that a man will gain any significant height past the age of 22; Paul was the same height in 1963 as he was in 1965. It seems highly unlikely that he would go for several years without any significant growth, and then suddenly, at the age of 24, suddenly grow between 2 inches and 3 inches to 6'1 or  6'2, suddenly looking over John's head. 
  

      The difference in height is immediatly obvious; his nose now rises well past her forehead, and her eyes are level with his chin. It is of course possible that she is wearing heels in one, but not the other. However, this change is perfectly consistent with the other photos shown above, as well as the scale comparison. 
     Another interesting note that may or may not be significant; notice where they are walking........A GRAVEYARD! Now, this is almost certainly a sheduled photo shoot for a magazine, and not just some nut with a camera following them. Why in the world would they pick a graveyard for the location? This is a completely contrived photo of a romantic couple on a quiet stroll........THROUGH A GRAVEYARD!