Of expressionism, Wikipedia says, “Its typical trait is to present the world solely from a subjective perspective, distorting it radically for emotional effect in order to evoke moods or ideas. Expressionist artists sought to express meaning or emotional experience rather than physical reality.” 
There are many ways to express meaning and emotions, including writing, painting singing, dancing, playing et cetera. Aside from writing, which necessarily engages the intellect, I think of expression as being on a large scale such as, big sweeping movements in dance; emotion-laden singing; arcs of a painter’s arm on as she sweeps a loaded paint brush over a huge canvas. The title of a biography I just started about Jackson Pollock says it all: Energy Made Visible. 
I have recently been trying watercolors in a 5X7 format. The best sweeping movement I can make is about 3 degrees of an arc, pivoting from my elbow, with my paintbrush in my hand. In terms of ‘energy made visible’, it is like working with an AAA battery powered Dremel  that is almost out of juice. How can one get one’s whole body involved on a 5X7 work surface?
Perhaps there is another way.
One thing follows another
Another mode of expression is to respond to a given stimulus. It is indeed possible to place a mark on a small canvas. Looking at this mark perhaps inspires an intersecting or parallel line to be drawn, or a drop of paint to be set free from a great height. The pair of marks then inspires the next action, and so on.
Although I wouldn’t exactly call this ‘energy made visible’, it does fall into the category of expressive art. The role that the body plays is diminished, but the mind is engaged by responding to the visual feedback of the previous marks on the paper.
I find myself creating this sort of sketch – actually, I would call it a doodle – when I am practicing my pen and ink shading strokes. These strokes are quickly drawn parallel lines of varying spacing that indicate a desired gray level in a pen and ink drawing. I tend to sketch eyes quite frequently in these doodle pictures. I don’t really know why.
Here is one of my small scale ‘expressive’ drawings: