Complicated because complicated in the object of portrait genre - human.
Fragile, because one mistake and works is over.
By the way... Portrait never can be just "Ok".
Portrait always is bad or good portrait.
Probably because of such strict criteria most contemporary artists try to avoid this genre of painting.
But inside category of realised portraits always exist the same dillema - bad or good.
Why? Because if in portrait accent is on the only beautiful young woman's face, it is not enough to be real portrait . true portrait should declare personality of the model. Without personality stay only manner of painting and we realise that all portraits are portraits of one abstract model.
Yes. Here may be excuse if it is not the portrait but more broad concept - genre portrait.
But genre portrait should be based on more complex composition....
But about it next time...
Alexi Borodin. Soviet artist