Why a why?? Isn't it obvious? Tidus is about to speak up when Roland gets to it first, and so he turns to him, oblivious to anything wrong or troubling here. Seeing the positives in it too, and again about to speak--

But then he interrupts himself, looking back to Inigo with some concern.

"It wasn't bad, was it? You seemed pretty happy about that last magazine, so I thought you'd like this too."

At least, he took the purchase as having some value to Inigo, but now he isn't sure if 'positive' is the right emotion to put to it. Would this just make Inigo think of his mother too much? And that wasn't the point.