Ads showing up in dashboard while using WP Dash Message (non-WPMU plugin)

I’ve just enabled Advertising in Pro Sites, and configured it to appear once per page, under posts and pages. I pasted in some code from my Google Adsense account. To my surprise I see an ad is also now appearing in the dashboard of user sites, within the output of a plugin I found called WP Dash Message. This is an older plugin but still seems to work fine, except for this unexpected behavior. I find this strange and would like to understand why it’s happening, and would like to know how to disable it. Any ideas?