Some background:
North Dakota State is a serious FCS powerhouse. They have won 7 of the last 8 FCS championships. They legitimately compete with Power 5 teams when given the chance. If they were in the BIG10 tomorrow, they're probably finish in the middle of that conference.
The Bison are very run heavy. In 2018, for example, they ran the ball 670 times and threw it only 290. So receiving stats are suppressed just by virtue of the system.
From 2015-2017, Shepherd averaged 42 receptions, 592 yards, and 4 touchdowns.
In 2018, he caught 62 passes for 1065 yards and 9 touchdowns. These marks led the team in receiving categories by a huge margin. The next highest in receptions had 23. The next highest in receiving yards had 389. The next highest in receiving touchdowns had 8 (a TE who caught 14 passes total), but the next highest wide receiver had 1.
His punt return production makes him interesting. For his career, he's returned 44 punts for 578 yards and 1 touchdown (13.1 YPR). In 2018, he returned 19 punts for 296 yards (15.6 YPR).
So his production was fantastic. Athleticism is where he fails to impress. He came in at his pro day:
5'10 186 lbs
4.57-4.61 forty (29th%)
35.5" vertical (~50th%)
7.13 three cone (~17th%)
So he is a highly productive receiver who is undersized, below average athletically, and making the jump from the FCS level. That will make him an interesting test case. These quicker than fast slot types sometimes don't test well, but end up being productive (Jamison Crowder comes to mind). So we'll see.