LocalViking

Local Viking Has 2 Options on how to  Bulk posting Images 

The gallery option found at <a href="https://localviking.com/gallery" rel="nofollow noopener noreferrer" target="_blank">https://localviking.com/gallery</a>, houses all of your locally uploaded images (over the last 10 months) and also allows you to upload images directly in bulk for multiple locations. Check more info <a href="http://help.localviking.com/en/articles/5279295-the-image-gallery">http://help.localviking.com/en/articles/5279295-the-image-gallery</a>

 Multi-Location Media can be found here     <a href="https://localviking.com/gmb/multi_location_media/new" rel="nofollow noopener noreferrer" target="_blank">https://localviking.com/gmb/multi_location_media/new</a>

1. The gallery option found at <a href="https://localviking.com/gallery" rel="nofollow noopener noreferrer" target="_blank">https://localviking.com/gallery</a>, houses all of your locally uploaded images (over the last 10 months) and also allows you to upload images directly in bulk for multiple locations. Check more info <a href="http://help.localviking.com/en/articles/5279295-the-image-gallery">http://help.localviking.com/en/articles/5279295-the-image-gallery</a>
2.  Multi-Location Media can be found here     <a href="https://localviking.com/gmb/multi_location_media/new" rel="nofollow noopener noreferrer" target="_blank">https://localviking.com/gmb/multi_location_media/new</a>

Allows you to upload one image into Multiple Locations 

Choose a category that you have in your GBP otherwise your image 

<b>Fallback to "Additional" Category </b> button, helps you to prevent the image from getting rejected if it doesn't associate with a category that had been chosen

and it will be placed in an additional category 

After that just upload an image or choose from a gallery ( all the images that have been  uploaded prior)

Choose all the locations that you want to  upload your image, or a tag(allows you to group locations)