A micro-chart or a miniature version of a chart can be inserted in a Counter Chart on Smart Report. To quickly visualize the trend of measure values (y series) against dimension (x axis), you can choose a micro chart inside counter chart of a smart report.
The below example shows a micro-chart in Counter on dashboard. You can optionally choose to select an aggregation function like sum, average, count etc. to calculate the field value on the y-axis.