It seems the explanations of reverse 2♠ are correct,but Gib E don't tell me how many cards in ♠,Usually reverse 2♠ means Gib have 4-card ♠ and values in it.
For this hand,Gib E reverse bid 2♠ only with two card,it is a short suit,and must be alerted.but Gib E never do.
So I think reverse 2♠ with two card is a psyche bid,even a cheating bid.