Rising to the East at this time of year, the three stars of the Summer Triangle are bright enough to punch through twilight and even a little wispy cloud. To the naked eye they appear as three white/blue points of similar brightness, but this is deceptive.
The two stars on the right of the image - Vega and Altair - are indeed quite similar. They are both A-class stars, more massive and more luminous than the Sun. As residents of our neighbourhood they are among the brightest in our sky.
The most surprising thing about Vega and Altair is: they are not round. They aren't even close to spherical.