Detailed Instructions: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: What are bigger squares used for?, Context: A tile mosaic is a digital image made up of individual tiles, arranged in a non-overlapping fashion, e.g. to make a static image on a shower room or bathing pool floor, by breaking the image down into square pixels formed from ceramic tiles (a typical size is 1 in × 1 in (25 mm × 25 mm), as for example, on the floor of the University of Toronto pool, though sometimes larger tiles such as 2 in × 2 in (51 mm × 51 mm) are used). These digital images are coarse in resolution and often simply express text, such as the depth of the pool in various places, but some such digital images are used to show a sunset or other beach theme.
A:
express text