The Wix Member Signup is whatever signup/login method that you are using out of the three choices.
https://support.wix.com/en/article/about-the-member-signup-form
It looks like you are using the Wix Stores app and the Quick View gallery which should all work without the Wix Login window appearing.
https://support.wix.com/en/article/customizing-your-wix-stores-product-quick-view
If you have not used any code on your site for this then you would be better suited going through Wix Support for more help with this issue.
https://support.wix.com/en/article/contacting-wix-customer-care-for-support
If you have used code, then as you are posting this in the Wix Corvid Forum, please add your used code in a code block below.