1. The lumberjack song (I'm a lumberjack and that's ok) is a Monty Python sketch [0]
2. The song goes from the singer being proud he's a lumberjack to being proud that he puts on women's clothing and hangs around in bars, and wishes he were a girlie (just like his dear papa)
3. Trump and his administration is famously anti-trans and anti-drag
4. The current secretary of transportation was a lumberjack before
So, overall, the joke is that the secretary of transportation was a lumberjack, which has this comedic queer association because of the Monty Python sketch, that Trump would hate.
The Secretary of Transportation (who is allegedly trying to fold NASA into his own portfolio, and is openly feuding with Elon Musk) is a former lumberjack and became a professional competitor in lumberjack/tree climbing competitions.
He puts on women’s clothing and hangs around in bars.