Advanced ePub file working in Adobe, but not in other software - why?

Dear friends,

I have an interesting situation. I would be very grateful if I could receive some kind explanation to what is going on.

I have recently been part of creating an advanced e-book, with a lot of hi-resolution images together with text.

Now a professional publishing enterprise has helped us make an ePub version of the creation.

However, I have tried to open the file with various different softwares (on Windows 10): Bibliovore, Freda and ePub3 Reader, and for each of these three, the formatting of the book ended up as a total disaster. But however, when I opened the very same file in Adobe Digital Editions, everything looked absolutely fine!

Would anyone be able to explain to me what is going on here? I confess to being completely unfamiliar with the ePub file format and what it really is and how it is constructed.

Best regards,