I think its more of a "what are your interests/some good ECs" and do those mesh well with their mission. So like if you say you are bringing a big research interest, and its like a community focused school with very little research... thats not very strong. Whereas if they have strong connections with free clinics that their students can volunteer at and you can say you are interested in helping in local clinic stuff, you can back this interest up with experiences that you had in undergrad where you helped out at clinics.... stuff like that. The idea is to make sure your aspirations are in line with their mission/focus.
Thats at least how I have done it and it has felt right.