@andreww thank you for the explanation! This is what I expected. Kind of sad they didn't put it on the CD, there was still plenty space left.
Also, curiously, the 4.5 release looks just like 1.1 release https://www.os-museum.com/brightv/brightv.htm
p.s. Thank you for your OS archival and museum efforts :)
@nina_kali_nina B-right/V's appearance barely changed across versions, with probably the biggest change being the wallpaper. Even the last version of its 16-bit predecessor, 1B/V3, looks pretty similar (although 1B/V1 and 1B/V2 were much flatter). AFAIK there were some major changes between B-right/V versions that weren't immediately obvious (for instance, B-right/V R2 a.k.a. Chokanji 1 added support for all codepoints of the TRON character set and Chokanji 4 added shared libraries)