When viewing the battle replay, you can mouse over the cards to see what card got played, and that card pops up to the front when you hover over it.
An annoying thing I found is that even though the battle replay progresses from left to right, mousing over from left to right is troublesome because sometimes you can skip over a card as you hover your mouse through the battle.
Given cards A, B, and C close together in time:
Hovering over card A will partially cover card B, while card C covers the rest of card B, so if you mouse left to right, you go from card A to C, skipping B.
This can be fixed if cards to the left didn’t naturally cover cards to the right, but instead, the other way around.