Tommy did it because he saw those drawings in the newspaper clippings and I guess, being the prodigy child he is in that film, thought he could distract Jason by making him see a more human part of himself? A past of himself maybe?
Personally, I think it was just a gimick to get Jason distracted, like what we saw in Part 2 where Ginny puts on his mom\'s sweater, pulls her hair back, and tries to sweet talk him. They are all to put our big guy in a confused state so they can hurt him. Luckily he smarts up eventually... too bad for him in Part 4 though.. Wasn\'t fast enough.
Personally, I think it was just a gimick to get Jason distracted, like what we saw in Part 2 where Ginny puts on his mom\'s sweater, pulls her hair back, and tries to sweet talk him. They are all to put our big guy in a confused state so they can hurt him. Luckily he smarts up eventually... too bad for him in Part 4 though.. Wasn\'t fast enough.