Where does ice get the energy to lift sand adhered to its base as it melts?

Consider the following clip of ice melting on sand:

I’m intrigued by the fact that the sand below the ice lifts as the ice melts and the base of each cube lifts from the surface. Where does the energy come from to do this? Since the lifting comes from the deformation of the ice as it melts, my first vague guess is that the stress of the weight of the adhered sand somehow slightly increases the enthalpy of fusion, so the resulting air is slightly cooler than the same volume of ice melting without lifting the surface. In other words, I can only imagine that the energy comes from heat in the air, though admittedly I can’t substantiate any specific mechanism much.

^{The clip above comes from the first 2 seconds of the music video for JOYRYDE’s “DAMN”, which sourced much of the footage from Macro Room.}