It is customary to start by defining brand using the Bezos standard: Your brand is what people say about you when you aren’t in the room. I’ll add my own as-yet-unnamed corollary: Your employer brand is what people say about you when they aren’t on the clock.
That said, there are things you do every day, consciously or not, that influence, establish and define that employer brand. Are you a suit-and-tie kind of company? Do people bring their dogs to work? Quiet or cacophonous? Offices, bullpens or mostly remote work? Collaborative or competitive?
Those attributes and feelings make up your employer brand. How you express them in your content reinforces them to a wider audience, one that may not have any other information about your brand. If you’re a top brokerage house, you likely thrive on intense interpersonal and inter-team competition. If your content attempts to reflect a more collaborative environment, it won’t align. More accurately, it will gut and hollow out the intended message.
At this stage of the content creation process, you should have a firm understanding of who you want to talk to and what message you want them to hear. The brand element forces you to marry these external thoughts to the cold reality of who you work for.