Pick something you already have numbers for: commits per week in a repository, time spent per project, results from a feed an agent reads. Open a thread in the workspace that can reach that data.
Ask the question and ask for a chart, and say what kind if you have one in mind. "Commits per week for the last quarter, as a bar chart" is plenty. The agent gathers the data and draws the chart under its reply; see Charts in a thread for what happens behind that.
Now look at it with the agent. Ask it to check its own picture of the chart for crowded labels, to switch to a line, or to add a tooltip with the exact numbers. Each answer redraws in the thread.
If the data lives in a saved value that an agent keeps up to date, ask for the chart to follow that value. It will redraw by itself whenever the value changes, and Copy Shortcode puts it at the top of the workspace's prompt as a small dashboard.