If it's like the US version they'll just film until they get the reaction they want. They'll be no call to the diary room - they'll be directed within the house (or arena).Given the average age of the HMs was 30+, I wonder if they had to rally their enthusiasm? If I was in there, it's be a very cynical eye-rolling "Christmas in July, in fucking April?? Please we're adults here, why do you treat us like 8yos?" - and then be called to the DR to be told off by producers, followed by instructions to fake it for the cameras.
I also think now we've all experienced some kind of lockdown we probably all know that after a few weeks you completely over react to the simple pleasures.