Top icons are automatically sorted for consistency in articles. For that reason, |sortkey= should only be used in user top icons. Sort keys are sorted alphabetically, so, for example, "19" will sort before "2". If you want to use numbers as sort keys, and you have more than 10 top icons on a page, you must add leading zeroes, e.g. |sortkey=01, |sortkey=02, etc.
|width= and |height= are restrictive, meaning when one parameter is not set explicitly, the default acts as a maximum, even if the other parameter is set higher. To increase the overall size, both must be specified.