DNA? What is this?

Does anyone know what this is.. I can't remember. I got it when my son was born, never told me anything about it.. I had it put up.. its disappeared,When my other son was born.. my step daughter and I was taking pictures on her nannys old phone. I went back to delete and seen this picture.. so I got upset. My husband said they sent him this pic cause they think I had a DNA test down on our son.. lol I've been with one person. I know who my kids father is!! But I getting ready to confront them and I want to know what exactly this is.