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As Andrew stated the bounce is all about the second interaction not the length of time on the page. You are encouraging that second interaction, but don't get hung up on the bounce rate entirely, I rate user experience over everything else.

Having your images open in a new tab rather than a lightbox of similar takes away the users ability to navigate your site. If you are viewing on a phone for example a new tab is a pain to close. I prefer to be able to hit the back button or a cross in the corner of the screen. If I had to close a new tab every time I think I'd leave the site alone.

CONTENT IS KING

Without content there is nothing to rank. Who wants to link to a noninformative site?  The algorithm looks for content as do human visitors therefore, Content IS the holy grail.

Hi

Because you are duplicating the site it is bad for SEO. To address this you need to add the canonical tag to the master page. I'd look at your analytics to see where the majority of your traffic comes from, either mobile or desktop and add it to that version of the page.

More info on that here: https://moz.com/learn/seo/canonicalization

I hope that helps.

No problem, Unfortunately, most people do view on a mobile device these days. Just having a responsive site sometimes is just not enough when it comes to user experience.  Good luck!

If you are using anchor text that is not on the landing page it sends mixed signals to the search engine. Remember that search engines are just complex directories trying to give the user the most relevant result. If your keyword doesn't match the page it's linking to then the likelihood is it will lose its relevance equalling a lower authority signal and lower SERP.

If you are using a relevant keyword for anchor text then you can weave it into the landing page.

Hope that helps