It might be based on the Toyota Yaris Cross.
The trademark attorneys at Toyota are staying busy by filing applications for the names "LBX" and "Lexus LBX." It's not entirely clear what this moniker might be for, though. Lexus Enthusiast first discovered the requests.
On August 5, Toyota filed a trademark application of "LBX" in Europe. On the same day, the company also requested "LBX" and "Lexus LBX" in Israel. Then on August 7, the automaker submitted the paperwork for "LBX" in Iceland and Switzerland. All of them are in the category for "automobiles and structural parts thereof."
Given the locations of all of these trademark requests so far, it makes us think that the LBX would be a European-centric creation. However, since the Lexus brand's start, the brand's models use alphanumeric model names consisting of two letters and numerals referencing the powertrain. LBX doesn't fit the normal nomenclature, and there's no indication of the marque overhauling the branding scheme.
Lexus Enthusiast speculates that the trademark could be for a forthcoming concept, and there's evidence to support this theory. A rumor suggests that the Toyota Yaris Cross could get a Lexus variant that the company would call the BX. The little crossover would sit below the UX in the lineup. If the marque wants to preview the vehicle at a future show, then LBX would be a fitting name for it.
Gallery: 2021 Toyota Yaris Cross
Since the Yaris Cross is for European and Asian markets, it would make sense for Toyota to apply for the trademark for the Lexus version in those areas first.
Toyota also recently filed trademarks around the world for "Lexus RZ 450e", including in the United States, Europe, and Australia. It's possibly the name for an electric crossover coming from the brand.