I think she was upset at first, but the whole thing about going again, particularly when Ant said she couldn't, smacked a bit of a tantrum. Sorry, this is just my opinion, and I based it on how it appeared on screen. Other people may have a completely different one.
However, when my 18 month old has a tantrum and cries, there are almost never any tears. However when she is really distressed, I can tell almost immediatly. Not saying this makes me an expert.