If you would like to share your My Homes Room to the Gallery, make sure to toggle the Sharing button "ON" before submitting your room.

Before you submit your room, you will see an option to "Share this room in My Homes Gallery."
To toggle on, tap the sharing button "ON", this will share your submitted room to the My Homes Gallery.

Please Note: You have to select the Complete button to send your My Homes room to the My Homes Gallery.