Want to display visual-left hint to perplexed users that explains what your visual is supposed to reveal? Like me, you have missed the handy Power BI help tooltips feature that allows you to pop up some helpful text for each visual.
This works best for blocks of information a person needs to see once. Rather than it showing up every time you visit the page, make it available via a tooltip. You’ll want to make sure the tooltip is readily visible for people new to the report but not so overwhelming that it annoys people who already know how this thing works. That, however, is a completely different challenge.