I read somewhere that Trump lent him a jacket for that photo because he didn’t have one that day.
Trump is a much bigger man, and that’s why Cruz looks so odd in the pic.
The Trump loaned Cruz a jacket is a Cruz-supporter myth. In fact, Cruz has a fetish for ill-fitting clothes. Pay particular attention to the photo of Cruz in a trench coat. One hand is completely engulfed in the sleeve, while only the fingertips are visible from the other.
http://jezebel.com/why-dont-ted-cruzs-clothes-fit-him-1693371534