Help with rejected photos by quality issues

There is a slight issue with the histogram.

Your asset is missing blacks (left). I would also enhance the local contrasts (texture/clarity) of the assets.

As for the yellow teeth: we all want to get out teeth white in a photo. You should, however, not overdo that, so that it looks unnatural white.

I've made a few changes, hopefully it's a bit better than the original. I'm still learning how to edit photos and sometimes I'm not sure if I'm improving on making the photo worst! haha

Hello,

I would say you have to improve your white balance - just a bit.

E.g

And add more contrast and increase the exposure - make the photo a bit brighter.

In my view, I don't think you have to make the teeth white - unless you are advertising teeth whitener/toothpaste to make your teeth whiter etc.

Teeth are not naturally 'white.' (As snow!)

Maybe the color cast? I went for white teeth here.