The church has been vacant since 2021 and plans to turn it into homes have already been rejected.
Created through layers, the portrait aims to show the human cost of the Post Office scandal.
The Post Office counter in East Hagbourne's community shop has been closed since February.
Post Office is in talks with parties interested in taking on the branch, described as a "lifeline".
Billy Burrows and Alex Bake have been making social media videos about their Sheffield Post Office.
Former sub-postmaster Lee Castleton was falsely accused of stealing from the branch he ran.
Firms are concerned the closure in Wellington, Shropshire, will negatively affect their work.
The Post Office says it is advertising for a new operator to take over the Wellington branch.
Paul Patterson will become the chair of Fujitsu's UK business responsible for its inquiry response.
