Responses
I just saw so many comments saying how lewd her thoughts her but this was how I saw it from the start to be honest, she conjured up images to descriptions when people read them out in their heads, hence when Mana described her bra she didn't use a lot of detail which left Aya to interpret the style of bra with Mana only describing the colour and pattern.

I don't think that she herself has perverted images to go with his thoughts I think it's more like he describes it in his thoughts which caused her to create these images based on the descriptions. It's like reading a book, you aren't perverted if it explicitly describes a scene which you then picture within your mind.