It is impossible to store a png/jpg image to a TInyDB. How are you storing a picture to your TinyDB? Are you converting the image to Base 64 text and saving the Base 64 script? Are you attempting to load text into a BackgroundImage? (that can not be done).
See [Free] KIO4_Base 64. Extension for File to/from Base64 for one way to convert between png and Base 64
If you want to post text to the Canvas you have to use this Block
