Isn't "twice" a valid translation too?
Yes it is, for one of the translations: "two times", not necessarily "over two times". I can't see the difference. Twice means two times.
I don't think so, because "twice" would mean that you would see the same photos again.
Twice could also refer to seeing the photos in two sittings.
twice should be acceptable. indeed
No, it is not acceptable: please read the whole thread for details.
Notwithstanding the subtleties being discussed here, if "But you will see them two times, because there are many photos." is one of the correct answers, then "twice" means the same as "two times" here, and should be accepted.
Wouldn't over two times mean more than two times, whereas "en deux fois" would mean "twice"
In French "en deux fois" means that you will see the photos in 2 sessions: photos 1 to 50, then photos 51 to 100, each photo being seen once.
So does it mean, in effect, that you will have to see the photos in more than one go because there are so many?
The English sentence doesn't really clarify this, maybe because we don't really have a corresponding phrase.
"in two gos" is the usual term. Not that I got this right. I said "twice" Very subtle.