What does this number measure?
A concentration of dozens of clusters linked by filaments. Published extent scale of the galaxy concentration, not its distance of about four billion light-years. The IUCAA release uses the rounded figure of 600 million light-years. Other texts give about 200 Mpc, a similar but not strictly identical rounded value; the definition and boundaries of an overdensity depend on the survey and cosmology.
Compare the stated dimensions
The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.
Source and limitations
The IUCAA press release uses the rounded figure of 600 million light-years. Other texts give about 200 Mpc, a similar but not strictly identical rounded figure; the definition and boundaries of an overdensity depend on the survey and the cosmology.
A generic artistic pattern shared with another entry in the same family; it represents neither a photograph nor an observed map of this structure. The galaxies and filaments are symbolic; only the stated extent follows the length scale factor.