You open up Jacob's file and give it a lookover. Male, 5'10" who likes cartoons. Slightly above average intellegance and looks. Loves his mom and family. Likes his roommates, but finds Gina a little annoying. Nothing surprising in the file. Well, what are roommates for except to make life more interesting for eachother?
You erase Jacob's like of cartoons and replace it with a joy to watch documentaries, and put the file back in the file cabinet. Within seconds, the zaps and noises from Rick and Morty turn into nature sounds and some guy talking about various birds of the rainforest. This could be fun.
Trying something different, you change hair from short to long before putting the file away, and his hair grows past his shoulders and then gets a hair-tie in it. You stop when Billy started talking to Jacob, who doesn't seem to be freaking out. There is no comment about the hair. Its like it was that way the whole time. So, personality changes and physical changes work for the characteristics fields that are there, but what about putting in something new?
You put in a new characteristic; breasts 34C. After waiting a moment, you put the folder back into the cabinet. Standing up and walking out, you see Jacob from the back with long hair. Taking a seat next to him, you see he has some breasts, but no bra.
"No bra today Jacob?" you ask
"Home is where the bra comes off, bro."