This logging level is just for help in debugging, generally it should be left at 'Warning'.
The 'INFO: No representing image in folder...' will appear when you have deselected 'Settings > Advanced > Use thumbnail for folder icon'. As it says, it is just for info., when logging is set to 'Warning' that would not be shown.
By 'co-incidence' that setting is what sections.inc line 5
appears to be looking at:
var getFolderThumb = function(ao) {
var vars = ao.getVars(),
s;
// Iconpath => SVG, folder thumb path
if (s = vars.get('iconPath')) {
s = s.replace('folder.png', defaultFolderIconName);
return s.replace(/^\.\.\//, '');
} else {
return createFolderThumb(ao, folderThumbSize, true);
}
},
Something for Laza to look at.