After doing all my testing with the random portriats mod on I've belately found out that there is a clash between the two mods. The order shown in the mod screen is important. If you have my mod in position 0 and randomportraits in position 1, some code is overwritten and there will be no mirror at game start so the mod will do almost nothing. To get it to work, put randomportraits in position 0 and my mod in position 1.
Believe it or not, the obvious fixes don't work so for now please put the mods in the right order.