Ricky Pearsall is a good athlete; he doesn't possess elite speed, but he has very nice quickness thanks to a low center of gravity, which can be deceptive and lead us to believe that he is very explosive, although he is not elite in that regard. 
He has good changes of direction with fluid hips, excellent coordination, and very good upper body flexibility; Pearsall can be described as a fluid mover.
The biggest weakness in Ricky's physique is his muscular power; there is no moment of true dominance from him in all aspects of his game.

Pearsall is a very good route creator; being a fluid mover with very good quickness allows him to have no latency in his breaks, which are very incisive and executed almost perfectly.
However, he needs to simplify his routes; even though trying to break his defender's ankles is very fun for him and the viewer, he really needs to simplify his routes because sometimes there are too many unnecessary movements in his route that cost him time. 
Even though he creates a lot of stress on opposing DBs, the fact that he thinks he's in a 1v1 drill without a time limit doesn't help him give his QB a chance to release the ball quickly. 
He has a fairly developed route tree, and he should have no trouble expanding it even more in the NFL; he is a precise route runner who knows how to use tempo well in his routes.

Ricky Pearsall has a nice variety of releases against press coverage; he is explosive enough at the LOS but doesn't use his arms well on the initial punch; against more physical CBs who are not afraid to put their hands on him, it will be difficult for him to get off.
Against press coverage, his ability to create separation is limited vertically due to his speed, as mentioned above. I'm talking here about simple routes like a fade; if asked to run a post or a corner, he might be able to create separation during the break, but he might take too long to develop his route against NFL-caliber CBs.

Against off-man coverage, he is very good because he has time to create stress on the CB, but he does not have the athletic ability to separate to attack the third level (deep), especially when lined up on the outside.
His head and shoulder fakes are elite; he has a very good ability to manipulate opposing CBs.

Against zone coverage, Pearsall is very intelligent and knows when to sit in his route to give a viable option to his QB or create off-script opportunities.
Pearsall has the ability to be a big problem on the first two levels (short and intermediate) of the field in the NFL.

Pearsall has a big catch radius; he is capable of making absolutely magnificent acrobatic catches. Overall, he has excellent hands with good technique (only 6 drops in his career). His excellent concentration and elite eye/foot/hand coordination allow him to make the best adjustments to throws in his draft class.
I don't think he's a receiver who will potentially rack up a lot of yards after the catch in the NFL, even though he can be creative in this area with good vision; he resembles more of a possession receiver. He could take balls on jet sweep-type plays because he has the moves to elude defenders, but his lack of speed and explosiveness, coupled with a lack of power to break tackles, will severely limit him in YAC situations or as a runner.

In run blocking, Pearsall is very active, but here his lack of power will be a problem in the NFL; he also needs to work on his blocking angles and redirections, but overall, it's quite solid.

Ricky Pearsall is an interesting prospect because he has the tools to create stress in defenses and will have to be respected both on the outside and primarily in the slot. Even though he is not an elite athlete, he "plays fast" (Comparison to Cooper Kupp for playing fast but not being an elite athlete), and I attach a lot of importance to this quality coupled with his "baller" talents.
If he can simplify his game, there is no doubt that he will be an important element of an offense and could become a high-volume receiver.
I evaluate Pretty Boy Ricky, as my friend @FranceGators would say, as a talent in the 3rd round.