Explain the joke

The image uses the Big Bird puppet (from Sesame Street) in a corporate setting to humorously contrast how startup founders and self-employed individuals are treated when applying for mortgages.The joke is about how banks and lenders often treat startup founders and self-employed people as strange, risky, or hard to evaluate when they apply for a mortgage.Even if they are working seriously, the lack of a simple stable salary makes them look absurdly out of place in a formal financial process.