Assert the browser is on a named administration screen, or not. It is the check of a role's landing page: after login every role lands on the Dashboard, except a subscriber, who lands on the Profile.
Examples
Then I should be on the "Dashboard" admin screen
And we should be on the "Profile" admin screen
Then I should not be on the "Dashboard" admin screen
And I should be on the "Posts" admin screen
Then we should not be on the "Plugins" admin screen
Pattern
Then(/^(I |we )*should( not)* be on the "([^"]*)" admin screen$/, …)
Part of @webship-js/wordpress-steps (github.com/webship/wordpress-steps), a step pack for Webship-js 2.0.x.