Hello,
The sourcecode of the gallery is something like:
<div data-carousel-extra='{"blog_id":1,"permalink":"https:\/\/www.actualidadmotor.com\/prueba-mazda-mx-5-rf\/"}' id="gallery-2" class="gallery galleryid-224616 gallery-columns-3 gallery-size-thumbnail"><dl class="gallery-item"><dt class="gallery-icon landscape">
<a>https://www.actualidadmotor.com/prueba-mazda-mx-5-rf/prueba-mazda-mx-5-rf-40/</strong>"><img width="150" height="150" src="https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-40-150x150.jpg" class="attachment-thumbnail size-thumbnail" alt="Prueba Mazda MX-5 RF" srcset="https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-40-150x150.jpg 150w, https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-40-300x300.jpg 300w" sizes="(max-width: 150px) 100vw, 150px" data-attachment-id="224709" <strong>data-permalink="https://www.actualidadmotor.com/prueba-mazda-mx-5-rf/prueba-mazda-mx-5-rf-40/"</strong> data-orig-file="https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-40.jpg" data-orig-size="830,553" data-comments-opened="1" data-image-meta='{"aperture":"5.6","credit":"","camera":"NIKON D3300","caption":"","created_timestamp":"1485338015","copyright":"","focal_length":"18","iso":"400","shutter_speed":"0.008","title":"","orientation":"1"}' data-image-title="prueba-mazda-mx-5-rf-40" data-image-description="" data-medium-file="https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-40-300x200.jpg" data-large-file="https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-40.jpg" /></a>
</dt></dl><dl class="gallery-item"><dt class="gallery-icon landscape">
<a href="https://www.actualidadmotor.com/prueba-mazda-mx-5-rf/prueba-mazda-mx-5-rf-30/"><img width="150" height="150" src="https://img.actualidadmotor.com/wp-content/uploads/2017/01/prueba-mazda-mx-5-rf-30-150x150.jpg" alt="Prueba Mazda MX-5 RF" /></a>
Here you can see all WordPress attachment pages like data-permalink="https://www.actualidadmotor.com/prueba-mazda-mx-5-rf/prueba-mazda-mx-5-rf-30/ and data-permalink="https://www.actualidadmotor.com/prueba-mazda-mx-5-rf/prueba-mazda-mx-5-rf-40/",
so when googlegot access to this post it can see and follow all attachment pages. We have around 200.000 images on this site so googlebot has to follow 200.000 url’s only to see a 301 redirect, that’s not good for google.
We want to optimize crawler bugdet and for this reason I need to avoid googlebot can discover attachment pages. Now I think googlebot can only discover attachment pages in jetpack galleries.
regards,