The Last Reproduction Steps section keeps a tally of the last step a customer took before the error occurred in each session. The same error may occur at multiple steps in the customer journey, but through the running count you can identify the step or steps at which the error usually occurred. This could be a click, a text entry, or a backend process like a page load.
Click on one of the reproduction steps to open a list of sessions that showcase the error at that reproduction step. This may give further insight into how the error impacts the customer journey.
Learn more about the other sections on the Developer tab: Stacktrace, HTTP Error Details, Browser & OS Impact, Insights, and Top URLs.