Should there be a difference between tone/personality in certain essay prompts

For comparison, I will reference stanford's room mate essay vs the general "Why major" essay.

Logically, you would want to sell yourself as a personable, likable person in the room mate essay(for example: 'heya, its ya room mate here. In case you're hungry there's a pot pie i baked for you in the oven!'), but would you want to employ this same tactic in the 'why major' essay? I was thinking that the 'why major' essay would be much more straightforward in tone and have more references to the things that an applicant has done/achieved to show interest in a certain major.

Am I wrong?