I'm sure there will be a big list of portraits via DLC and mods. But until then, this is my contribution. Check the description for more details.
Download the file or this image:
C:\Program Files (x86)\Shadowrun Returns\Shadowrun_Data\StreamingAssets\ContentPacks\seattle\art\portraits
This will replace the faceless human male portrait. Just change the 3D model to look like the image.