The text is only part of the initial info the model uses to create the image - the settings and the random number seed are other parts that are relevant here because they’d be the same for both images. The seed in particular is why these images look so similar - normally when you give the same prompt twice, the seed is randomized so the model starts from two different points. Here, each model starts from the same point and works the same way, just with different amounts of data, so a lot of the details are shared.