Nice portrait, but... Maybe it's just your scans and if so, please disregard my comment, but on my monitor(s) your plates often look overexposed. In this case, the nose, left cheek and forehead appear washed out and nearly featureless. This is the most common error people seem make when first delving into the collodion process, followed closely by over development. Also, based on your exposure, I presume this was a bright sunny day. Softer light and some shadow fill will help tame the contrast.