Thumbs up for Ava's answer - steganograpy alone can be detected and if using plain text easily deciphered.

So make sure you first encrypt your secret/seed/nsec, then use steganography to hide encrypted text into the file/photo/document.

My advice would be to start small (don't play with your btc seed just yet). Instead you could try hiding a "secret message" within your art and give instructions to decipher it to whoever buys the piece.