Rejection - tips

[Neli_Hristozova1676]

Hi! Recetly many of my images got rejected and I don't get why. It says quality issues, but they seem fine to me. 
What do you think about these images, what is it that I am not seeing? 

[daniellei4510]

Numerous drawing errors. I've indicated only a few.

[Jill_C]

Zoom in closely and inspect carefully and you'll see many drawing errors.