The sub folder contains all the legacy photos from iCloud and iPhoto and normally should have photos and videos.

With 10.10 and the new Photos app, everything appears to be stored in ~/Library/Containers/com.apple.cloudphotosd/ and not in Application Support once you open the new Photos app and allow it to migrate things.

If you're in that situation (open the Photos app once and letting it set up a library and choosing which Photos to store locally), you should be able to confirm that nothing in iLifeAssetManagement is needed anymore and safely delete it after making a backup offline just in case we don't know all the tricks Apple has pulled.

Be sure to open iPhoto one last time and see if you need any of the photos there. If not, consider deleting that app and then converting all the iPhoto albums into Photos app albums and deleting the iPhoto Libraries once you have also an archival copy of these Libraries for "just in case" needs stored offline.

Docker is an automation tool, which facilitates deployment of applications using Linux feature called Linux Containers. Docker provides neither virtualization nor emulation environments. As of today, running Docker containers requires using Linux (support for other operating systems, like Oracle Solaris and Windows Server is in the development phase).

Docker for Mac and Docker for Windows are separate products that run a Linux virtual machine inside the host OS and provision containers inside that machine.

There is no way of running a Linux virtual machine in iOS, hence iOS cannot be a "host for Docker".

Besides operating system, even if you ran Linux on iOS, you would need to also consider the CPU (that is also true for Raspberry Pi recommended in the comments under the other answer). Most available Docker images use binary packages for Intel/AMD architecture, not ARM limiting the use cases compared to running it on MacBook.