This grid displays the commit hashes for the head of each lab branch you have pushed to your private gitlab repo. Each row indicates for a particular student the set of commits that will be used for grading.
User ids are random, but deterministic - they will remain stable over the course of the semester. To figure out which user id corresponds to you, fork the cs6450/labs into your own private gitlab repo, clone your private repo to a local repo, create a branch called 'lab1', and push lab1 back to your private gitlab repo. The grading script runs once an hour on the hour. After you push the new branch run git log to and look at the first 4 characters of the commit hash for the head commit on your lab1 branch. After awhile you should see the first 4 characters of your lab1 commit hash show up in the table on some row - that row is the row that corresponds to you.
Congratulations, you've make a submission which is eligible for grading. You can continue to push new commits up until the deadline for each lab; after a particular lab the grading script will stop pulling commits for that branch.