In a nutshell:
This movement includes glass rendering effect used in an unexpected context, being applied to objects such as chains, flowers and hearts. The effect of this is that it throws the viewers expectation, forcing them to reimagine how they feel about these objects, and what their use is. This visual tool is used in a range of ways, often to exaggerate delicacy or used as a visual juxtaposition, something delicate contrasted with something strong like chains.
Another idea that underlies this visual theme is the contrast of natural vs manmade. This is really apparent and literal in ‘Engine your Heart’ by alekscg. In the mentioned example, this theme is explored with the use of engine-like cogs and valves, perhaps, alluding to more sci fi themes of man and robot.