#QBasic, <s>151</s> 122 bytes
Really just for fun (via QB64) - it doesn't golf well 

Taking some `ABS()` inspiration from [Joffan's VBA answer](http://codegolf.stackexchange.com/a/87509/44821) but applying it differently:

    FOR i=-25 TO 25
    FOR n=0 TO 25-abs(i)
    s$=s$+chr$(n+65)
    IF n THEN t$=t$+chr$(90-abs(i)-abs(n))
    NEXT
    ? s$+t$
    s$=""
    t$=""
    NEXT


Previously:

    FOR i=0 TO 25
    p(i)
    NEXT
    FOR i=0 to 25
    p(25-i)
    NEXT
    SUB p(i)
    FOR n=0 TO i
    s$=s$+chr$(n+65)
    IF n THEN t$=t$+chr$(65+i-n)
    NEXT
    ? s$+t$
    s$=""
    t$=""
    END SUB