The key parts here are the enctype attribute on the form tag, and the “file” input
type for the user_pic. These lines set up the form to upload not just text, but also
a binary image file.
Figure 8-3 shows that the page already lets users select an image. But there’s something
else this HTML needs: a size limit on the image. You’ve gotten that email from
a friend that’s 22MB and has a picture of a cat blown up to 100 times its normal size,
right? You want to avoid that in your forms. No 22MB cat images; a single megabyte
or two is plenty for any reasonable profile picture.