Yes I know...
I also don't like modifying content, and it is the very first time I do it, and I hope, the last time.
Unfortunately, as said in the change log section, it was impossible to resize the original portrait to EE size without pixelling. I searched through the web and did not find any pictures that might help me. So I decided to take the PPE ones, otherwise EE compatibility would have failed. But...
There is a legacy sub-folder in the mod top folder where I stored all original content I modified : old readme, wav files (I converted them to ogg format), unused scripts, the two components GB removed from his mod AND... the original portraits. If you play original BG2, copy them into your override folder.