My mother says if I have pictures of babies in my room, it will positively affect my unborn child. Is this an old wives tale or is there some scientific explanation?

Maybe she means looking at pictures of happy babies will lift your spirits and keep you happy thus in turn, you'll have a smoother and more relaxed pregnancy? I've heard of the whole look at pretty people to get pretty babies superstitions but I don't really buy that myth. But having eye candies during pregnancy can't hurt right haha.