  In this work, we examine the optical behaviors and thermodynamic phase
structures using shadow analysis for four $\mathbb{S}\mathbb{T}\mathbb{U}$
black holes. The study is conducted for four cases of charge configurations on
the parameter space $\mathcal{M}\left(q_1,q_2,q_3,q_4\right)$. As a matter of
fact, both the electric charge as a parameter and the parameter space
$\mathcal{M}\left(q_1,q_2,q_3,q_4\right)$ affect the geometry of the black hole
shadow, particularly the size of the shadow. We also introduce a constraint on
the charge of the black hole from the observational results of the M87$^\star$
{\color{black}and Sgr A$^\star$} shadow. Furthermore, we show that the electric
charge and the parameter space $\mathcal{M}\left(q_1,q_2,q_3,q_4\right)$ have a
non-trivial impact on the variation of the energy emission rate. Interestingly
enough, we find novel scenarios in which the evaporation is slower, which
causes the lifetime of the black holes to be considerably elongated. On the
other side, the phase structure of four $\mathbb{S}\mathbb{T}\mathbb{U}$ black
holes is explored for two cases of electric charge configuration. The findings
show a perfect correlation between the shadow and event horizon radii. This
correlation is, in fact, helpful in discovering the phase transition in terms
of the shadow radius. In addition, the microstructure is being analyzed in
terms of shadow analysis, providing similar behavior to the ordinary situation
of the Ruppeiner formalism.
