This is far away from High Key. skin tones seem to be way off, tilted lines on the background distract. lacks of contrast. blue frame hurts the image, irregular black frame doesn't make sense at all
The perspective and modest nature of this shot is very nice. The technical quality in sharpening is better than most entries in this challenge.
Hate to disapoint you, but this is not high key photography. The hallmark of high key is the luminosity light curve (or histogram) weighted to the right side of the graph on your main subject. This indicates it contains more light to white pixels than dark. Your main subject has more dark pixels than light.
Nice high key. Could probably be even brighter to be high key. composition and crop are great. I think seeing a face profile would help make the image better.