Don't all teams have the same salary cap, as set by the league? This graphic doesn't make any sense.
I assumed it meant cap space. If you go to overthecap.com it shows Miami having nearly $62 million available next year.
Guys who I assume will play a role this year who are unsigned for next - Gesicki, Ogbah, A. Wilson, E. Roberts, Needham, P. Williams, Eguaveon.
Those guys alone aren't eating up $62 million but between a few them and possibly some free agents to replace bust rookies/young guys that amount will reduce very quickly.