Prevent biblatex date output for online citations

I'd like to not print the year (nor a possible author), but only for Online types of citations.

Here's an illustration of what I would like to remove (in red):

Here's my MWE:

% arara: xelatex
% arara: biber
% arara: xelatex

\documentclass{scrartcl}
\usepackage[backend=biber,style=authoryear,sorting=nty]{biblatex}

\begin{document}
Example\cite{tab:test}

\printbibliography
\end{document}


mwe.bib:

@Online{tab:test,
Url                      = {http://www.example.com/images/image.jpg},
Urldate                  = {2014-02-25},
Timestamp                = {2014.06.13},
Note                     = {Table \ref{tab:test}}
}


This question is motivated with difficulties in resolving Custom biblatex style for citing images and tables, and represents a narrower requirement

This will remove the date. But note that this code will print only the 'Note', 'URL' and 'URLdate' fields in the bibliography for bib items of type 'online', even if there are other fields

\documentclass{scrartcl}

\usepackage{filecontents}
\begin{filecontents} {mwe.bib}
@online{tab:test,
author                   = {Doe, John},
Url                      = {http://www.example.com/images/image.jpg},
Urldate                  = {2014-02-25},
Timestamp                = {2014.06.13},
Note                     = {Table \ref{tab:test}}, %not sure I understand why you are cross-referencing here
year                     = {2014}, %this is necessary for the in-text citation to work
}
\end{filecontents}

\usepackage[backend=biber, backref=true, style=authoryear, sorting=nty]{biblatex}

\DeclareBibliographyDriver{online}{%this defines what will be printed in the bibliography for entries of type 'online'
\usebibmacro{note+pages}