There's a textile dust overlay image (or more likely a fill pattern made of a dust photo), a grey background and the written paper is a separate layer with a drop shadow. It's between the grey background and the dust overlay.
If you watch carefully, you can see the dust pattern is the same on both pages, only shifted and it's repeated even in one page. That proves it's an overlay. A real paper hasn't repeating fibre patterns.
You can check it by yourself for ex. layering the pages and having in the top layer blending mode = multiply. You find easily a layer placement where the dust particles fit. Here they are a little shifted vertically:
Very likely all images and texts on the paper are also separate layers between the white paper and the dust, except the face. The person obviously thinks she is worth staying above the dust.
I have made a resembling dust image by brushing a cloth above the glass of a scanner a while and scanning the result against a white paper. People who own film dias get the same effect simply by storing a dia on the table few days. If you want it without tinkering, purchase a stock image with a dusty dia texture.