General developer forum

This is the proper code

$user = (object) [
'id' => $teacher->id,
'picture' => $teacher->picture,
'imagealt' => $teacher->fullname,
'firstname' => $teacher->firstname,
'lastname' => $teacher->lastname
];

$options = array(
'visibletoscreenreaders' => false,
'includefullname' => false,
'alttext' => true,
);
$item .= $OUTPUT->user_picture($user, $options);