How a Kilt is worn is not a function of how much yardage there is in the Kilt as it is how the Kilt was made to Fit.

I, as a maker of Contemporary Style Kilts, allow the customer to determine the Fit of their Kilt.
A Traditional Style Kilt however is supposed to Fit with the top straps cinched into the Natural Waist. On most men the Natural Waist is not found by looking at the stomach but by feeling around back near the spine.

If you place your hand with the fingers along your spine and move it up and down you will probably find three places where there are hollows that a Kilt could be cinched into.
The highest will be just over the Kidneys and just below the ribs. This is your Natural Waist. It will also be just above any "Love Handles" you may have.
The next lower spot will be in the Nape or small of your back. If you cinch the straps into this area the Kilt will sit just on top of the Pelvis bones.
The lowest spot will be down at the area where your Butt starts to jut out. This is where Blue Jeans are worn.

It would appear from the photo that the Kilt you are wearing is designed and made to sit at the Midddle cinching place. (What I call Mid-Rise)

A Prince Charlie Jacket is designed to be worn with Kilts made to cinch at the higher level or Natural Waist. (What I call Full Rise)

A Traditional Kilt should also have 2" of Rise above the top Straps. The Kilt should flair out above the straps allowing it to ride up and over the lower ribs slightly.

So, If your Kilt was made to ride at Mid-Rise then perhaps you should not wear this Kilt with your Prince Charlie Jacket.
The other thing that may happening is that the Kilt was not made with the pleats flaring out above the straps. This will cause the smallest part of the Kilt to nestle into your Natural Waist and the whole Kilt to ride too low.

And then again, Perhaps it was a good party, perhaps it was late in the evening, perhaps the Kilt just slipped down while the photo was taken. And perhaps you were just standing funny for the photo to be taken. I know I would probably stand funny with that tall turbaned fellow that close behind me.

Put the same outfit on again and look in a full length mirror. That's the only real way to tell what happened here.