Hi, at the open day they said that both the mini portfolio and full portfolio should show your strongest and most proud work - so it's safe to say they will and should overlap in their content. Basically the reason they invite you for interview (if they do) is that they found your work to be interesting and believe you have potential. The actual interview is then there to determine whether you can actually articulate your work and process/thoughts well when they ask you about it, I think especially because they really want to know if you're a well-rounded passionate creative that can go deeper about their art than just an uploading an image. So yes, definitely include the stuff from your online 'sneak-peak' in the real portfolio because that's how they would have become interested in you in the first place..