Wasn't too obvious to me, in other words completely missed that one, but maybe someone else has too:
The "If condition" branch allows an array in it.. in which case the true and false branches are evaluated depending on the condition result for each array item. It's not possible to do things like "accumulation" of array items however because theoretically, all the branches could be evaluated in the same moment. ... see the "iterate on array" for things like that.
This tree sets all array items < 12 to the minimum of the array.
