Summoning A Mob With Blocks in a certain way

So, my structure of blocks is different from the way that an Iron Golem or Snow Golem is spawned. So, I tried doing the procedure, just with different coordinates, but it didn't work. This is the way I would like it to spawn:

https://imgur.com/a/acvMJbl

Below the structure is the code I tried to do to make it summon, but it did not summon anything. Yes, the structure is lying against the ground, not standing up. If you could help, that would be amazing, thanks!