The experimental study has been carried out using advanced computer vision method in order to visualize the moment of excitation and further propagation of a non stationary isotropic domain in a hybrid aligned nematic (HAN) microsized volume under the effect of a laser beam focused on a bounding liquid crystal surface. It has been shown that when the laser power exceeds a certain threshold value, in bulk of the HAN microvolume an isotropic circular domain is formed. We also observed a structure of alternating concentric rings around the isotropic circular region, which increases with distance from the center of the isotropic domain. The formation of a sequence of rings on a polarizing microscopic image indicates the formation of a complex topology of the director field in the HAN cell under study. The following evolution of the texture can be represented by two modes. Firstly, the "fast" heating mode, which is responsible for the formation and explosive expansion of an isotropic zone in bulk of the HAN microvolume with characteristic time due to a laser spot heating on the upper indium tin oxide (ITO) layer. Secondly, the "slow" heating mode, when an isotropic zone and concentric rings slowly expanding with characteristic time mainly due to the finite thermoconductivity of ITO layer. When the laser power significantly exceeds the threshold value, damped oscillations of the isotropic domain are observed. We also introduced the metrics that allows quantitatively estimate the behavior of texture observed. The results obtained forms an experimental basement for further investigation of thermomechanical force appears in the LC system with coupled gradients of temperature and director fields.