Pic is out of focus even when zoomed in and lightened...
....but could be porosity(candle egg to check) or speckles(better focused pic would help).
'Speckled' eggs can happen for several different reasons...very few, if any, of which are a 'problem'.
Can be caused by:
Excess or uneven pigment coating.
Excess or uneven cuticle(bloom).
Excess calcium deposits.
Porous eggs can appear speckled.
Some birds lay them consistently, some only once in awhile.
The pigment or bloom can change appearance when wet, then change back when dry again.
As long as bird is getting a good diet and is healthy in every other way, it is no cause for concern.