Is raising one's hands in a "show of takbir" without the intention of prayer or uttering it considered mockery of prayer, reaching the point of disbelief, even if it was unintentional and done quickly?

This act is not considered mockery of prayer unless one intends it as such; rather, it is merely an imitation of its movements, and its purpose might be educational. However, this is strongly prohibited so that it is not mistaken for mockery or belittling of prayer, and a Muslim must exalt the status of prayer.