When you notice the stripes

Riddle me this: why does a print change the way something fits? 

I've noticed this a lot over the years, and it's always puzzled me. I guess I can understand if the print is applied on top of a fabric, maybe that changes the way it stretches or falls or something. But if it's just dyed differently? I do not get it. Recently, it's been with these tees from UO. I bought one a couple months ago, and fell in love immediately, deeply and madly. It fit so perfectly, loose and flattering but still figure-skimming. And super soft in that washed out cotton kind of way. And the color, a muted but still vibrant blue. I loved it. I wanted it in every color I could get my hands on. 

So a couple weeks ago, I went back. They had a sadly small number of them in my size (only 3), but I bought all 3. Of those, 2 were solid colors, 1 was striped. All are the same material. The striped one is tight as a tick and so low cut I couldn't wear it to work. The solids? All lovely as the original.