Iasha was far too nice and meek to stick her head up above the parapets between Thomas and Lottie, and I can't blame her for it this week!
The problem is there have been too many weeks when she was only visible when she walked into the boardroom through the whole episode, and by week 6, two moments of shining through by that point isn't enough (TM for the bikes, although that had cringeworthy moments, and blagging the concept of the slime unicorn kingdom). She seems like a lovely person, but just not the right personality to be a serious contender.
Over the years there have been contestants like Thomas who've been in the boardroom and final line up a lot but go a long way to the final few. They normally have ideas even if they don't work brilliantly and a spark about them that appeals to Suralan. There have also been candidates that win consitstantly that get to the late stages, but he's had little opportunity to get the measure of in person. I suppose their resiliance to faliure is a major consideration for him.