Layla's nationality only bother me to the extent that she had obviously followed BB closely in the UK, and since the Australian show tends to copy the UK one, she had the advantage of knowing what "tricks" were coming next (ie the "second" house, etc). She's been one step ahead of BB the whole season. She's obviously a huge BB fan.
What bothers me about Layla is her (to me at least) obvious attempts to entertain us by playing the airhead. Knowing BB inside and out as she does, there is no way she didn't know the meaning of the word "strategy". When you see her in serious conversations with other housemates, she uses intelligent language, but then pretends to not know what a hand grenade is. I don't mind when people "play the game". I actually like it, and I respect those who can do it well. However, it really bothers me when an intelligent woman "dumbs down" because they think that's what the public want to see. When she does it so badly that it's easy to see through, then that's just bad game playing.