For example, such requirement might seems logical if you are using image link and the information text is already in the image.
In such case, the labels redundant, but you can't hide them with the layout property, and no one want to build VF page just for hiding those labels.
The trick is in the label value. You cannot leave it empty, but you can add css properties (carefull, which attributes you adding!).
Before the label just add: <font style="font-size:0px">
Note that you might need to shortcut the previous text, but since you want to hide it, you won't mind.
The result:
