Thank you for the congratulations! 
Welcome back to the English side

Congratulations to Jokers for the new role. I don't fully know what his role will be, but the rank suggests he will be moderating subboards and their moderators as well. It looks like a heavy task, but his promotion says he is the right candidate, although I don't know what's the system here to promote him to this rank as I am not very familiar with the senate and president system of the forum yet.
To elaborate on this a bit, before Jokes was a mod of various sections, and now as global mod he is a "site-wide" mod (so can moderate the entire forum). Technically speaking, this is the only notable change to being promoted to global mod. There are other permissions that have been granted, mainly to do with punishing users (giving strikes and such), though these aren't exclusively global mod permissions either, and they had access to some prior to promotion anyway.
Jokers role is otherwise to carry on as they were doing, simply with more reach over the forum as well as it's users. This also means they no longer require global mod support when moderating, as they are able to deal with all topics. Previously they could warn/moderate a user, but not necessarily deal with all the posts for example, so this promotion is very much for technical reasons more than anything.
He was otherwise voted on by other global mods (as part of a gruelling 16 months process may I add), as explained in the original post. I wouldn't say he moderates other mods though, that job is mainly for President, VP, or admin, even though may act in a support role for mods of other boards, as global mods usually do.