Clear blue digital question!!!

So no this does not apply to me as I haven’t even ovulated and I don’t use digital tests, but my friend wanted me to ask on here as she’s super confused and I’ve tried to tell her not to open them but she did anyways and wants an answer

The clear blue digital tests with one strip- is there always 2 lines on there ? With the two strip tests there usually is isn’t there but I don’t know nothing about the one strip digital tests so I’m unable to help here! Hope someone can answer this

Thanks :)