# Font in theorem-like environment: why is it different?

I noticed that the \itshape fonts are not the same in this picture:

• What is the "name" of the \itshape font in the theorem-like environment, in this case?

• How could I force the "normal" \itshape font in the theorem-like environment? Or, how could I use the "alternative" \itshape font in a description environment? Piece of code:

{\itshape Soient $E$ et $F$ des ensembles finis et soit $f:E\longto F$.}

\begin{proposition}
Soient $E$ et $F$ des ensembles finis et soit $f:E\longto F$.\\
Alors,
\begin{description}[font=\normalfont\itshape, leftmargin=!]
\item[\quad a) $f\text{ injective}$]  $\impl \ \va{E} \leq \va{F}$
\item[\quad b) $f\text{ surjective}$]  $\impl \ \va{E} \geq \va{F}$
\item[\quad c) $f\text{ bijective}$]  $\impl \ \va{E} = \va{F}$
\end{description}
\end{proposition}

• What is a possible reason why they are different?

(of course, I would like to have the same fonts)