Can I come out to see it in the mirror?
'Uscire' — 'u-SHI-re'. Stress on second syllable. The 'sc' before 'i' = 'sh' sound.
When the fitting room mirror isn't large enough or you want to see the full effect. Common in boutiques with shared full-length mirrors in the main area.
'Posso uscire' = can I come out. 'A vederlo' = to see it ('a' + infinitive for purpose). 'Allo specchio' = in/at the mirror. 'Allo' = 'a + lo'.
C'è uno specchio fuori?
Is there a mirror outside?
Simpler — checking before asking to leave
Il camerino non ha specchio intero.
The fitting room doesn't have a full-length mirror.
Explaining why you need to come out
Esco un momento?
Shall I come out for a moment?
Informal and brief
Many traditional Italian boutiques place full-length mirrors in the main shop floor rather than inside fitting rooms. This encourages interaction between customer and staff, which is very much part of the Italian shopping culture.