  When a topological group $G$ acts on a compact space $X$, its enveloping
semigroup $E(X)$ is the closure of the set of $g$-translations, $g\in G$, in
the compact space $X^X$. Assume that $X$ is metrizable. It has recently been
shown by the first two authors that the following conditions are equivalent:
(1) $X$ is hereditarily almost equicontinuous; (2) $X$ is hereditarily
non-sensitive; (3) for any compatible metric $d$ on $X$ the metric
$d_G(x,y):=\sup\{d(gx,gy): g\in G\}$ defines a separable topology on $X$; (4)
the dynamical system $(G,X)$ admits a proper representation on an Asplund
Banach space. We prove that these conditions are also equivalent to the
following: the enveloping semigroup $E(X)$ is metrizable.
