That is an idiosyncratic usage of the verb disperse and the sentences do not seem to have been written by a native speaker. We spread messages; we do not "spread them out". We spread out a bed sheet or a tablecloth or a picnic blanket or a large map.
When a crowd of people breaks up, and the individuals go their separate ways, the crowd is said to disperse.
The crowd of protesters in front of City Hall has dispersed.
When a balloon is popped, the air inside the balloon disperses.
The word yourself refers, it seems, to your "brand identity".
The advice is, as you have surmised, to remain focused in the brand proposal and not to touch upon diverse (self-) branding strategies.