He didn't caption the post, but many saw it as a "flex" from the politician who already has a hit song named after him.
While some were impressed, others joked that pupils would "eat pilchards and garlic" at the school, making reference to the dishes the minister often posts on social media.
The majority zoomed into the picture and realised the letter he had posted was for a temporary substitution teacher position that expired on Wednesday.
They lambasted the minister for sharing old job opportunities and told him to sit down.
Here are some of the reactions:
