I made any changes according to Sasha comments, Thanks, very much...
Hi, Sergio!
I didn't think that you take my remarks so direct.
In my view that picture is better.
But...
There is in the top left-hand corner some cusp node. Why? All background has wavy-line contour. It needs replace.
In previous picture the shoulders of president are equal with background. Now don't. In previous it was better. Upon my word.
The dark shade into ear must be brown too (dark brown).
Three new ideas.
1. What do you think about to do all lines in different colours.
Lines of face - brown (dark brown).
Hair's lines (end eyebrows, of course) - black.
Coat's lines - dark blue (coat accordingly light blue).
Shirt's lines - grey (same shirt - white).
Tie's lines - dark green.
Background - without lines (without contour).
2. Common background is a rectangle. You did it as wavy-line (rectangle). It is yours author's decision. Not bad. But CorelDRAW save (or export) drawings as rectangles. (All what exist are rectangles.)
I offer to do rectangle (more than wavy-line rectangle), put it dawn and colour more dark or less dark as background (on your taste).
3. You are coloured (all details) in monochrome palletes: colour - shade.
I think be better palleters (from light to dark): highlight - colour - shade - contour (see previous point).
I.e. it needs add some highlights: on hair, on forehead, on cheek, on collar of shirt, on shoulder of coat (all is left).
And to end.
You made splendid drawings. Why don't you have some stamp-signature with your name and year?
Good drawings!
Sasha.