Horizontally line up elements on button?

Get started
1

Hello,

I’d like to line up children of a button horizantally, like this:

    lv_obj_t *btn = lv_btn_create (page, NULL);
    lv_obj_set_size  (btn, lv_obj_get_width_fit(page), 132);
    lv_obj_set_pos   (btn, 8, 8);
    //    lv_obj_add_style (btn, LV_BTN_PART_MAIN, );

    LV_IMG_DECLARE(icon_60x60_settings);
    lv_obj_t *img = lv_img_create (btn, NULL);
    lv_obj_set_pos   (btn, 8, 8);
    lv_img_set_src (img, &icon_60x60_settings);

    lv_obj_t *lbl1 = lv_label_create (btn, NULL);
    lv_label_set_text (lbl1, "some text");
    lv_obj_set_pos (lbl1, 100, 8);

    lv_obj_t *lbl2 = lv_label_create (btn, NULL);
    lv_label_set_text (lbl2, "more text");
    lv_obj_set_pos (lbl2, 200, 8);

Unfortunately, the calls to lv_obj_set_pos() semm to be ignored. The sub-objects of the button are composed vertically.

Any hints what I am missing here?