It's from the counterfeit Heroic Spirits event. Jalter wanted a harem of fake male servants for her otome shtick, but a fake Bryn was accidentally included (obviously meant as a reference to the yuri route sometimes in otome games). Fake Bryn is obsessively in love with Jalter, which is why pretty much all of the depictions of Bryn and Jalter have Bryn being the affectionate one.