Joshua sat modestly in the same location last year, full of admiration for his most dangerous foe to date. Respectful of Klitschko's longevity, he accepted the 'little bro' comment that was surely part of the wily veteran's pre-fight indoctrination. Back then, Klitschko took all the liberties of an older brother but Joshua has evolved and grown immeasurably since.
He loomed both verbally then physically over his 21st opponent, fellow world champion Joseph Parker, at Wednesday's press conference inside the Sky Sports campus, where the 'little bro' joust was delivered and accepted on his previous visit.
'Klitschko had the authority to call me 'little bro',' Joshua explained.
'We're all relatively equal now - Klitschko reigned as champion for 10 years. None of us have been doing it for long. Well, Deontay Wilder has, to be fair. But he hasn't fought the opposition that Klitschko did.
'I'm still his little bro, man. Big respect to Klitschko and what he's achieved.'
But Parker? The unbeaten WBO heavyweight champion from New Zealand with giant Pacific Islanders wrapped in flags among his entourage looked at his most confident since this fascinating unification fight was announced, yet Joshua exercised the control that he lacked 11 months ago.
He won't accept being called 'little bro' ever again - 'No,' Joshua said. 'And, if they did…'
He towered over Parker during their face-off like a hungry lion sizing up his prey, his body language making the travelling fighter fully aware of who possessed the most imposing physique.
That subplot will continue at Friday's weigh-in when their measurements will reveal more about how this fight might end, but for now, advantage Joshua.
'Parker has a presence. Ultimately, it's about his skill and will rather than his presence,' Joshua said. 'If you want to talk about presence, I am the bigger man and the taller man. I weigh more than him. It's not the size of the dog, it's the size of the fight in the dog.'
Parker is no shrinking violet - in the past week he has been decked out as a Peaky Blinder, then wore glasses concealing superpowers more appropriate for Peter Parker, never mind Joseph Parker.
He and his support-base did not flinch amid argy-bargy with the Fury clan last September, 24 hours out from beating Hughie.
Perhaps ominously Parker arrives for his second fight in Britain in a similar position as Joshua was in before his Klitschko extravaganza, as a one-belt champion desiring a standout result to catapult his reputation.
That puts Joshua in the authoritarian shoes that Klitschko wore as the elder statesman at Wembley, right?
'No,' Joshua barked. 'You've got to be the current and the future. That's what Klitschko did to gain authority. He beat the current and the future challengers. I give him that respect.'
Joshua, in turn, has beaten champions from the past and champions of his generation already. After Klitschko's USB stick shtick last April, it was Joshua delivering knockout predictions on Wednesday.
He has sold quarter of a million tickets, boxed at two stadia and knocked out two men since being labelled Klitschko's 'little bro'. He has evolved into the older sibling of the heavyweight division but is astutely aware of the threat a young pretender can bring.