Thank you very much for the correction, it already works perfectly in standard mode !!
Unfortunately, it does not work in grid portal mode. That alt="" command is not shown and there is no view.php file to modify here...
I have tried, in the articles, to add an introduction image with a description, although it is intended to show the first image of the article.
Looking at the module files, I have located "echo" from the image. I don't know if it will help and maybe by adding some command here I will be able to show it.
Thanks for the invaluable help.