Will the popup be the same in every page of my site?

It’s up to you: you can select the popup you want to show in each page.

I have set the “Social network” section, but I am not able to display the selected social buttons in the popup!

Make sure that the popup you have created is a “Social network” type: this is vital to show the social network buttons you have selected.

I need to suggest a product in the popup, but the product image doesn’t show correctly. Why?

The image might be too big for the popup size and you may need to resize it. Use the “Customization” tab in the popup settings to make the image fit the available space.
Try to enter this rule in the CSS text box and the original image will appear:
ypop-modal img{ max-width: 100%; max-height: 100%; }