Looks like the terrible photo filters from smartphones have infected those photo booths as well. Just adding some decals isn't enough anymore. At least Himeno isn't one to add animals ears or whatever.
@givemersspls I suspect she doesn't love him as much as she's in love with love itself (like Soul Eater Not eloquently put it, if memory serves). She's pseudo-mature, always looking up to her big sister and trying to emulate her. I'd say she mainly chose Ouji because she had had some interactions with him, he's not ugly, and so forth. She's not really capable of romantic love, like the title itself already says, so it doesn't particularly matter who the target of the emulated love is, as long as she can fool herself into thinking he's participating in her make-believe romance.