What advice might you give to an individual contributor on a marketing team who feels detached from senior leadership?

It could depend on your level in the organization.  If you're at a lower level, then the answers below could be helpful.  However, if you happen to be in a role that isn't a priority for the business, and that's why you don't get exposure (higher priorities), then I'd suggest you start to look elsewhere, preferable inside your company.  If not, you'll continue to get frustrated.

Push for opportunities to showcase your abilities to senior leaders. Ask your manager to give you the opportunity to present a project that you've spearheaded and make sure to highlight the positive business impact your efforts have or will make. If your manager is not giving you the opportunities to do this, then find a different manager or job because that what successful managers and leaders do - encourage, empower & grow the next generation of successful leaders.

I am a big advocate for mentorship programs within the organization. These give staff an opportunity to talk to executives who are in different parts of the business, who are more experienced at the vice president or executive Vice President level and have a view of the overall business.