What ODD Contains
An ODD file is a ZIP archive containing XML documents that describe the drawing contents, styles, and metadata. When you convert a JPG to ODD, the image is embedded as a drawing object (<draw:frame> element) within the document. The output is a single-page drawing document sized to fit the image.
Software That Opens ODD Files
ODD vs ODP: What Is the Difference?
ODD is a drawing document (LibreOffice Draw). ODP is a presentation document (LibreOffice Impress / PowerPoint equivalent). Both are part of the ODF standard and both are ZIP-based XML formats, but they serve different purposes. If you need to embed a photo in a presentation, ODP or PPTX is the appropriate target format.
Is the Conversion Lossless?
The JPG image is embedded in the ODD file as a copy of the original JPEG data, so no additional re-compression occurs during the ODD wrapping step. The image quality in the ODD file is identical to the source JPG. If your source JPG already has compression artefacts, they will be visible when the ODD file is opened in LibreOffice.