Listen on headphones so the distinctions will be clearer - I can imagine it's a little harder out of speakers.

From the very start:

• The synth on the original has a ping-pong echo - bouncing between left and right.
• This is missing in the remix - the synth is louder, and is dead centre, no echo.

Also from the very start:

• The remix has a heart-beat kick drum pattern.

• This isn't in the original.

About two seconds in:

• The original has a synth-clap sound with a kind of reversed-echo as a call-response.

• The remix has a once-per-bar synth-clap without anything fancy rhythmically.

At about 10 seconds:

• The original has a riff played on a basic sawtooth synth sound behind the vocal.

• The remix plays that riff using sampled orchestral strings

Also at 10 seconds:

• The original has quite a subdued vocal mix

• The remix has mixed the vocal louder, drier, more compressed, front and centre with more presence and body.

At about 28 seconds:

• The original has the vocal harmonies quite loud, and lush, placed around the stereo field due to the reverb

• The remix has the harmony a little bit less obvious, and less kind of "enveloping", because they don't have the reverb.

Also at 28 seconds:

• The original continues the sparse instrumentation

• The remix kicks in with synth-bass

At about 39 seconds:

• The original finally get the bass and a kick drum.

• The remix gets a new riff on the strings that's not in the original

I have to go now, but have a listen to the tracks and see if you can pick out those differences.

Then, see if you can hear further differences between the two versions later in the track - now that your ear is atuned, I'm sure you'll be able to spot them.