So a trade works like a release.
The player's remaining prorated signing bonus accelerates and hits the cap immediately.
2016 prorated signing bonus - $3,629,636
2017 prorated signing bonus - $3,629,636
He also received a roster bonus this year of $1,844,818 on the 5th day of training camp.
There is a 2017 rooster bonus of $2,767,227 that hasn't happened yet so it doesn't apply except for the fact that the team that traded for him would inherit it.
His 2016 base salary is $600,000. So he currently counts $6,074,454 (base plus prorated bonus plus roster bonus) against the cap.
Overthcap is saying after June 1 the dead money hit drops down to $6,764,454, which is a difference of $690k from his normal cap hit. His base is $600k so I'm not quite sure where they are getting that additional $90K from.