Lemon always tastes good in tea. Hot, cold or whatever. I disagree with the topic premise.
However you probably wouldn't want lemon in your tea and milk or cream too. I'm pretty sure that would taste bad!
I like Thai (iced) tea. Most versions of that have a dairy product. (Or many versions, I don't want to argue about it.) I'm pretty sure Thai tea rarely or never has lemon in it.
I can't tell you what lemon and milk in your tea tastes like, but it looks yucky. As a kid, I was used to drinking hot tea with milk and sugar. This was not something any of my friends drank. I remember going to a restaurant with my Girl Sprout troop. I ordered tea. They brought lemon and milk. I didn't think about it; I just added both. Oh boy did I feel silly when I saw it. D'oh!