At the second panel it was drawn that way so that it shows specifically what Ayumi’s looking at. Because as you can see in the first panel the author drew the whole body, indicating that both us and Ayumi would be looking at the whole picture first BEFORE looking at the butt. In the 5th panel if Ayumi’s glasses had a reflection it would have created no suspense and it would NOT be appealing because it would certainly be boring. By showing his eyes, you can see the hunger and thirst which makes the reader excited for what is about to come next. Also the second panel is too small to create any suspense, you wouldn’t really be able to see his eyes. This is just my opinion tho
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No, because in the whole picture the curvy butt was the highlight of it all. And if they showed his eyes at the second pannel it would have looked hotter because we would see his eyes just looking at his ass. The reflection of the glasses means suspense anyway, if you didn't know, so if they put it in the 5th pannel, it would have been better as we would really want to know what Ayumi's gonna do next
http://www.mangago.zone/read-manga/fushidara_na_hanatsumi_otoko/mi/099e3966120641c6472c6cb93c8b6403_chapter-2/14/
I think in here it would've been hoter if we could see Ayumi's eyes behind his glasses at the second pannel as we already know what he is looking at, the author didn't have to specifically draw it. And at the 5th pannel it would've been better if we could only see the reflection of tha glasses instead of Ayumi's eyes, just a way to make it more appealing to the eyes of the readers