tall glass of water

Here's an answer on Stack Exchange that really expounds on the cause of the expression than you likely needed: http://english.stackexchange.com/questions/235815/what is calling somebody a-drink-of-water tl;dr : It used to be Scottish, it alludes to a tall individual, it was critical in certain specific situations, yet it was received by the Americans and inevitably changed to infer tall and appealing.

The accentuation should be on a tall appealing individual. Nowadays you commonly observe this expression come up on TV or in films as a bygone expression from the southern US. I would envision the expression proceeded there on the grounds that it's hot, and a tall glass of water is invigorating. It is like stating to somebody "Well, don't you look tasty" in the event that they were extremely appealing. (Yet, don't do that. It's too unpleasant. Like "tall glass of water," it's extremely just something that old Southern grandmothers can pull off, it's as yet odd when they do it.)

"Tall glass of peaches" is blending articulations. In a comparable bygone Southern way, considering somebody a peach demonstrates that they're alluring or potentially sweet. (You may see some person consider his secretary a peach in a film from the 50s, for example.) We appear to have a great deal of articulations for eating or eating up somebody on the off chance that they're adorable as well as appealing. I don't have the foggiest idea why that is.

I don't think "tall glass of water" solely depicts men, yet once more, it's an expression that is extremely antiquated and is currently for the most part connected with old Southern ladies inferring more youthful men are alluring. So it would be exceptionally unusual for you to express that to a female. Not on the grounds that it's a manly expression, but since you'd sound like a dreadful old woman or an investigator in an old film noir film, neither of which is most likely what you're going for. ;)