While the loading screen itself is a reward for completing the mission that concerns Fu teaming up with Bardock, the art in the loading screen references this part of one of the cutscenes in the mission.
From right to left Effloresced EGO Spicebush Yi Sang Hex Nail Faust Cinq Association Don Quixote Chef De Cuisine Ryoshu R. Corp Rhino Meursault Kurakumo Clan Hong Lu Sunshower Heathcliff Liu Association Ishmael Rosespanner Workshop Rodion The One Who Shall Grip/ N. Corp Sinclair 7 Association Outis AEDD Gregor
Same joke appears in post #7794758 and post #7915500. Google turns up this 2015 tweet, indicating that a) the joke is pretty old and b) the specific size is surprisingly consistent.