I thought I had addressed your optimization questions in detail here. You are gaining practically zero SEO benefit from the PHP loading of your photos – all your photos have the same description (in fact, for the link you provided, your SmugMug photos have no description), so waiting for a web-service round-trip is pointless. SEO may see the images, but it has no clue what those images are, and it will not associate any text with them.
Beyond that, there is already lazy-loading enabled on the photos, so regardless of your pulling 30 or 300 photos, that will not add any time to your website. In fact, while loading the page you provided, Photonic is way “below the fold”, so the photos from Photonic are not impacting your page load at all. Each photo only starts loading when they scroll into view. The only impact from Photonic is due to the PHP load mode. Take a look at the results from WebPageTest.org – there is no image from Photonic/SmugMug that shows up in the resource list (click on the “Waterfall”), because of the lazy-loading. The only blockers you have are:
- Time-to-first-byte, which will be impacted by the web-service call in the PHP mode – if you switch to JS, that time will go down. As such this is still < 1s, so it will only become faster
- Largest contentful paint – this is killing you, and is being caused because of various other inefficient elements on your site, like JS for the arrows on the page.
- Total blocking time – the additional JS is also being required for various other components on your page.
In my previous response to you I had already suggested that you can use the “Load More” feature of Photonic – you will see an option to include the button when you are creating a gallery. Bear in mind that if you are planning to continue using the PHP mode for SEO, then using the “more” button will defeat the purpose as your latter images will not show up in the crawl.
In short, currently the only delay you have due to Photonic is in the call to the server via the PHP mode, which is adding < 0.5s to the load time in the time-to-first-byte parameter. Nothing else from Photonic is impacting your page speed.
