The screen you land on after finishing a workout — confirmation that it saved, plus a quick recap.
The routine name, wrapped onto a second line rather than cut off if it's long, followed by the exercise and set counts, the total duration, and how many workouts (this one plus anything still backlogged) are queued to sync to the cloud.

A number still showing in "queued to sync" after you've reconnected just means the upload hasn't caught up yet — it'll clear on the next successful sync, nothing is lost in the meantime.
Related: "Logging a workout", "Starting a workout from your watch".