How to import files from one social. networks to another?

Question

css

I would like to know how the import of data, such as photos, from one social network works. networks to another.
For example, a photo downloaded from instagram can be instantly imported into VK. Or a special service www.thepo.st/ - you publish to one network, broadcast to another (photo albums).
Can this be done not only from my page, but also from a community or group?

Answer 1

via pseudo-elements :before and :after

Answer 2

In terms of technical implementation, it's just working with the social media API provided. For an example, you can see the VKontakte API - https://vk.com/dev/photos.get
If you are interested in ready-made services, then you need to google something like https://ifttt.com or the service mentioned above.