"In present-day English combinations of the progressive and adverbials of frequency often convey connotations of annoyance or irritation... See page 19 [here][1] [Tim Romano]" 

In American English, a great amount of time followed with -ing or a continuum , often presents annoyance, exaggeration,complaints or irritation. 

For example:  

>-You're always using the word like.
>
>-You're forever forgetting to emphasize the swells.
>
>-That dog forever barks when I get close.
>
>-Why does she always look at me like that? 


This is often how the progressive is used, but it's not a definite rule. The context usually makes it clear why you're using always for emphasis.


  [1]: http://clu.uni.no/icame/ij18/elsness.pdf