With accuracy report, you can check accuracy of tagging and measure performance of the prediction for a batch. Please note that you will be able to view accuracy report only for reviewed images in a batch.
On the matrix plot, the columns represent predicted values and the rows represent actual values. The diagonal cells indicate no of predictions that are correctly classified while the off-diagonal cells indicate no of predictions that are incorrectly classified. Accuracy score shows percent of actual tags that are correctly predicted. Accuracy is calculated based on recall rate.