This is really a cultural issue. In the US, pictures are a big no-no but in my experience with LATAM and European companies, pictures are common if not expected.
Design wise, the picture is a good opportunity for visual appeal.
Picture on resume is not mandatory. Users always can just to leave picture field blank and on resume it will shows default dummy/universal photo for all genders.
I don't think anyone would want a placeholder in their resume, but I agree that this being an online version, not having a picture is mostly an annoyance (you can easily find someones picture online).