"trickle-up economics" is in fact a very old and understood term on the left, as re-articulated from the previously deployed term "trickle-down economics", that refers to the movement of wealth from the middle classes to the upper classes, which defines the movement of wealth in the neo-liberal period. it refers to an increasing disparity of wealth that is concentrated in the hands of the rich, at the expense of everybody else.
i'll let stiglitz use it in context, as he's done much of the most important work on inequality over the last several decades. this is from 2010, apparently. but, i remember hearing the term during the anti-globalization protests of the late 90s.
the kids that are using this term to refer to something else need to read up on it's use in the recent past, and adjust themselves accordingly.