One image is marked with sRGB, and another is not

Hi,

I have two images and both are in colors, but when I click "I" in Adobe Lightroom, I can see that the first image is marked with "sRGB" and the second image / another images are not marked with "sRGB". I don't know why? And does this really matter? And how do I remove or add sRGB to the other images that are in colors.

Best Regards,

Gerhard Øpsen