Agreed.Assuming it’s an unaltered photo, it’s something military. There are precedents for military aircraft not being announced.
The photo reminds me of a UAP report I heard about, which involved a sighting over the North Atlantic. A guy, who was an expert in identifying aircraft when he served in the British Navy, spotted a triangular aircraft that he did not recognize. Not being able to identify it, it was considered to be an unidentified flying object. He probably saw the craft in the picture (A-12 or newer version of that craft).