Thank you very much for your feedback and time! We know that we do not cover aspects like skin tone - and we would love to somehow implement that. The problem is that to get the best statistical results, the "decision-influencing" differences between images ideally have to be reduced to just the exact condition (e.g. different breast size). Every other additional variation (e.g. skin tone) would "blur" the data. As we need 88 picture pairs to cover all required breast conditions anyways, it is practically impossible to take any other aspects into the survey (e.g. skin tone) without completely exploding the number of pictures and blurring the data. So we apologize for that "inconvenience" - but we haven't found a better solution. Thank you very much for your support and feedback!