I am an accountant, let me explain.
For an image 800 wide by 600 high
Take the width value and add on a software magnification factor of 800 (800 + 800 = 1600)
Add 20% VAT (1600 x 1.02= 1632)
Take the height value and add a software magnification factor of 800 (600 +800 = 1400)
Add 20% VAT (1400 x 1.02 = 1428)
Multiply the results by each other (1428 x 1632 = 2,330,496)
Deduct accountants fee of 2,000,000 (2,330,496 - 2,000,000 = 330,496)
Divide by golden mean (330496 / 1.6180339 = 204257.77)
Ascertain the square root of the result = 451.95
For an image 600 wide by 800 high
Take the width value and add on a software magnification factor of 800 (600 + 800 = 1400)
Add 20% VAT (1400 x 1.02= 1428)
Take the height value and add a software magnification factor of 600 (800 +600 = 1400)
Add 20% VAT (1400 x 1.02 = 1428)
Multiply the results by each other (1428 x 1428 = 2,039,184)
Deduct accountants fee of 2,000,000 (2,039,184 - 2,000,000 = 39,184)
Divide by golden mean (39,184 / 1.6180339 = 24217.05)
Ascertain the square root of the result = 155.61
Thus the net forum weighted value of an 800 x 600 image is 451.95 whereas:
The net forum value of a 600 x 800 image is 155.61.
The 800 x 600 image is therefore of greater value to the forum and that is why the lower value 600 x 800 image is not acceptable.
Obvious innit.