Can I have a different picture for pages, or do they all have to have same image?

Can I have a different picture for pages, or do they all have to have same image? (page 2 would have new image)

We use the same page background on the multi-page forms.

However, if you need different background images, you can achieve this with injected CSS.

CSS example for changing background on page 2 and 3: 

.page-section:nth-of-type(2) {
background-image: url(https://www.jotform.com/uploads/Mike/form_files/bg1.5d24edf3a162e2.00279626.jpg);
background-repeat: repeat;
}
.page-section:nth-of-type(3) {
background-image: url(https://www.jotform.com/uploads/Mike/form_files/bg2.5d24ee44e67006.73156365.jpg);
background-repeat: repeat;
}