Strange warning in TL 2025 about image resolution

[Enrico Gregorio]

Updated TL 2025 pretest on a Mac. Consider the input file
compiled with `pdflatex`:

\documentclass{article}
\usepackage{graphicx}

\begin{document}

\includegraphics[width=4cm]{example-image.pdf}

\includegraphics[width=4cm]{example-image.jpg}

\includegraphics[width=4cm]{example-image.png}

\end{document}

The console tells me

This is pdfTeX, Version 3.141592653-2.6-1.40.27 (TeX Live 2025) (preloaded format=pdflatex)
 restricted \write18 enabled.
entering extended mode
[...]
pdfTeX warning (ext1): too small image resolution ignored

pdfTeX warning (ext1): too small image resolution ignored

pdfTeX warning (ext1): too small image resolution ignored
[...]

The option “width=4cm” is just to avoid overfull box messages,
but it's irrelevant as far as the issue is concerned.

I also tried with other image files, with the same result.

Ciao
Enrico