It didn't seem a huge deception by lyra. I guess bears aren't that good at spotting a fib.
Not keen on the scenes in the 'real' world. I assume they'll tie up nicely, but really don't need them.
Armoured Bears are more or less impervious to being tricked, but because Iofur Raknison is obsessed with being as human as possible as is predominantly greedy, Lyra offering him something he desperately craves blinded him to the trick.
It does mention all this in the series but doesn't dwell on it - I probably noticed it because I've read the books and was slightly looking out for it.
I also preferred the bear fight in the film - Iorek smashing Iofur's jaw off was iconic (and how it happens in the book), whereas this tv adaptation had a bit of wrestling, punching and biting, but the actual death was hidden. Also, in the book and film, Iorek tricks Iofur into thinking he's more hurt than he is - which I took as Iorek realising that Lyra tricked Iofur, so perhaps he also could.
The 'our world' scenes are necessary. Will only appears in book two, but the TV series has spliced his backstory into series 1, which I think works much better
Spoiler
Will meets up with Lyra in the second book