To save the room to your library click on the folder icon in the bottom right corner of the window.
To add a room to the gallery go into build mode, click on the room you’d like to add to the gallery, in the middle navigation bar click on the folder icon and in the drop down choose “room”, enter a name for the room, to change the thumbnail click on the photo icon till you get an angle that you like best, in the information section select what type of room it is and provide a description, once complete click on the cloud in the bottom left hand corner to share to the gallery.
To save the household to your library click on the folder icon in the bottom right corner of the window. To add a household to the gallery from Create a Sim click on the “save household” icon in the top right navigation bar, choose a thumbnail by clicking on the photo icon until one you like appears, then add a description, once completed click the cloud in the bottom left under the description section to upload to the gallery. The Gallery is a place for you to browse, share, and download additional content created by members of the community without having to leave your game.