This image shows some kind of formula that could be converted to TeX . Storing formulas as images makes it harder to change them. TeX also helps making sure that they all use the same font and size.
A replacement has been proposed:

${\displaystyle {\begin{matrix}\quad E_{1}&{\xrightarrow {\ \ f\ \ }}&E_{2}\quad \\\pi _{1}{\Bigg \downarrow }&&{\Bigg \downarrow }\pi _{2}\\\quad X_{1}&{\xrightarrow[{\ \ g\ \ }]{}}&X_{2}\quad \end{matrix}}}$

In your article, replace the image with:

<math>\begin{matrix}
  \quad E_1            & \xrightarrow{\ \ f\ \ }   & E_2 \quad\\
  \pi_1 \Bigg\downarrow &                   & \Bigg\downarrow \pi_2\\
  \quad X_1            & \xrightarrow[\ \ g\ \ ]{} & X_2 \quad
\end{matrix}</math>