The recipient does not need to download the file immediately. TeraBox has a native MKV player that supports x264 codecs, meaning friends can Avengers: Endgame directly from the cloud in 720p.
The film's time-traveling mechanics allow for some clever interactions between characters from different timelines, leading to some genuinely emotional moments. The reunion between Tony Stark and his younger self, for example, is a highlight of the film, as is the poignant conversation between Captain America and a past version of Peggy Carter (Hayley Atwell).